Mohamed Abd El Ghany / Reuters

A man redraws the graffiti along Mohamed Mahmoud street, a day after the walls were believed to be painted by government workers to cover former graffiti, in downtown Cairo on Wednesday.

Under cover of darkness, a few municipality workers quietly began to paint over an icon of Egypt's revolution: a giant, elaborate public mural on the street that saw some of the most violent clashes between protesters and police over the past two years.

The mural, stretching three blocks along a wall off Cairo's Tahrir Square, has been a sort of open-air museum of the history of the revolution and its goals — with "martyr" portraits of slain protesters, graffiti, jokes, freedom slogans and pharaonic, Muslim, Christian and nationalist images to show Egypt's mixed heritage and a history of struggle.

Analysis: 'Manufactured outrage' behind Middle East protests

Word of the whitewash quickly got out. A number of progressive, young revolutionaries showed up to defend the murals. In the dead of night, they began to film the workers as they painted under the guard of police, hoping to embarrass them. They talked with the painters about what the murals meant.

The scene on Mohammed Mahmoud Street in the early hours Wednesday was a small but telling counterpoint to last week's angry protests at the U.S. Embassy, led by ultraconservative Islamists protesting an anti-Islam film. Those protests took place only a few blocks away on another street off Tahrir.

Together, the scenes point to the competition over the identity of the new Egypt, over what the country stands for now and what can be expressed.

PhotoBlog: Graffiti artists target whitewashed walls and the president

The mix of largely secular activists who launched the revolt against longtime leader Hosni Mubarak last year say the "revolution" is still continuing, until the country breaks with its authoritarian past and brings freedom and economic justice.

The Islamists, who rode to power after Mubarak's ouster, have their own vision for Egypt, which they say should adhere to an "Islamic identity" as they define it and preserve traditions.

'Erasing history'
The government says it has launched a campaign to beautify Tahrir Square, the center of anti-Mubarak protests. But activists saw it as a government attempt to blot out the calls for continued revolution and to assert that a new and stable system is now in place, under elected Islamist President Mohammed Morsi.

"They are erasing history," Gamal Abdel-Nasser, the father of a 19-year old killed during the early days of anti-Mubarak protests, said as he stood at the mural street. "This is not my government. It doesn't represent me."

Slideshow: Anger over film spreads throughout Muslim world

Akhtar Soomro / Reuters

Protests ignited by a controversial film that ridicules Islam's Prophet Muhammad spread throughout Muslim world.

Launch slideshow

And for some, repainting the wall just underlined the feeling that the Islamists have snatched the prizes of the revolution.

"This is not about the wall. It is about everything happening in Egypt," said Nazly Hussein, one of the first to arrive at the scene to protest the paint job with a camera, live streaming the workers as they covered murals. "It is about territory they took away from us."

The anti-film protests, she said, showed how under Morsi's three-month-old rule progressives were still having to fight for basic issues like freedom of expression. She pointed to government crackdowns on strikes and the recent sentencing of a Coptic Christian to six years in prison for insulting the Prophet Muhammad and Morsi. Still unaddressed are bigger goals of the revolution.

"This is about lowering our ceiling. Our real battle is about freedom. Now we are fighting about the right to insult the president or not," she said. "All those on the wall died for bread, freedom and social justice," she said, referring to the martyr portraits.

Egypt issues arrest warrants for Terry Jones, Coptic Christians over anti-Islam video

After the intervention by activists, the municipal workers stopped the whitewashing at daybreak with only half the mural painted over. Graffiti artists moved in to start putting new images on the now white walls. By late Wednesday night, the municipal workers hadn't returned to finish their job, amid a media uproar over the mural erasure.

The first drawing to go up was a portrait of a young man sticking his green tongue as a taunt. "Do it again! Erase, you cowardly regime," was written beneath it.

'A worse dictatorship'?
Graffiti artist Ahmed Nadi painted a new caricature of Morsi, smiling smugly, with the words, "Happy now, Morsi?"

Ali Saleh, a 53-year old security guard at a nearby school, said the murals must stay as a reminder to authorities of the mistakes they committed.

"If we give up the graffiti, this would be the first nail in the coffin," he said. "We are in for a worse dictatorship than Mubarak's."

The sense of progressives that the wall is their territory is deepened by its location. Mohammed Mahmoud Street saw dozens killed late last year and early this year as security forces repeatedly tried to crush youth protesting against police brutality and the military rule that followed Mubarak's fall. Morsi's Muslim Brotherhood and other Islamists refused to join the protests.

How rap music fueled the Arab Spring

Several of the activists accused the government and other Islamists of focusing on anger over the film to distract from the lack of real change since Egypt's first free election over the summer brought Morsi to power.

"Is this what will take Egypt forward now? Erasing the graffiti?" a school student in his teens shouted as the artists began to refill the wall with images.

"So long as we can't talk freely in this country, we still need walls to paint and songs to write," said Amr, an 18-year old commerce university student, refusing to give his last name because of security officers who remained nearby. "We are trying to be free. They don't want us to go down this road. They don't want a thinking people."

'Can't have a revolution every day'
Many Egyptians, however, say they just want stability after more than 20 months of turmoil. Some residents of the Mohammed Mahmoud area were happy to see the murals go, ending a reminder of the battles on their doorstep.

"This is ugly," said Nour Nagati, referring to the graffiti of a man with his tongue out. "Paint me a flower, paint me a tree. This is a symbol of stability. But this provocation will only perpetuate provocation."

Another resident in the area, who says he lived in Germany for 20 years and is an agricultural engineer, objected to the new graffiti artists over the words "cowardly regime" they had just scrawled on the wall.

"Why should I wake up and find this profanity scribbled on the walls. I am Egyptian. This is not my culture. This is only for the Westerners," said the man, who wore the small beard of a conservative Muslim. He refused to give his name.

But the lines are not black and white in Egypt: Age can be as much a factor as ideology. A younger man in his 30s with the even longer beard of an ultraconservative Islamist interjected and defended the murals.

"Why the distinction between West and East when it comes to freedom of expression? There is no doubt that whoever represses and breaks up protests is a coward."

The engineer looked at him in surprise, thrown by the idea of an ultraconservative defending graffiti.

"You're mixing everything up!" he cried.

Abdel-Karim Abu Bakr, a passer-by, said the time for using the walls for protest was over.

"We had a revolution, we changed the regime. Let's calm down ... We can't have a revolution every day."

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Slideshow: Graffiti Games: UK street artists take on Olympics

Jim Seida / NBC News

Street and graffiti artists have been satirizing, celebrating and making jokes about the Olympic Games in London.

Launch slideshow

Updated at 6:50 a.m. ET: LONDON -- An athlete steps up to take his throw -- except he is holding a missile, not a javelin; a pole vaulter soars high, but seems headed for a landing on a moldy mattress; an Olympic mascot's leg attracts some unwanted attention from a passing dog.

Banksy, whose works routinely sell for tens of thousands of dollars, and other street artists could hardly let the London 2012 Games go by without having their say -- despite the legal risks.

While at least four graffiti artists have been arrested by police ahead of the Games -- then released on bail conditions designed to prevent them from making their mark near the venues -- London is full of art works ranging from crude and comical to heavy satire to straightforward celebration.

A piece by artist Jimmy C. is among the latter, a large spray-painted mural of Jamaican sprinter Usain Bolt's face with streaks of vibrant color radiating outwards on the side of a row of houses in Shoreditch, not far from the Olympic Park.

He could only afford the $1,500 cost of the painting after he sold more conventional artworks at a gallery show in Paris, France, and had some money left over from paying his rent.

"People pick up on a spiritual narrative in my paintings," he told NBCNews.com, explaining that when he went through art school painters like Caravaggio and Velazquez were among his favorites and may have influenced his work.

“Some street art is very quick, humorous and political …  I try to create more lasting things with human qualities that everyone can identify with," he added.

'A very charismatic guy'
East London resident Jimmy Cochran, 39, as he is known in ordinary life, admitted he didn't know too much about the Olympics before deciding to paint something. He said he'd asked friends in Britain and Australia, where he grew up, what they thought about the Games.

Slideshow: When the Olympics is your neighbor

/

A diverse community in East London will welcome the world to Britain for the 2012 Olympic Games. Meet residents and hear how they feel about having a huge, world stage in their backyard.

Launch slideshow

“He [Bolt] kept coming up in more ways than one,” he said. “I thought ‘OK, this is interesting.’ I looked him up online, looked at images of him and realized he was a very charismatic guy, a big personality. I was drawn by his features.”

He painted the image on a wall often used by street artists, but didn't ask permission from the owner, who Cochran said he had been told was in Greece.

Teen held after Olympian gets Twitter death threat

Unlike Cochran's picture, Banksy's works, which appeared on his website without any explanatory comment, have a clear political edge.

Banksy rose from being a small-scale street artist to an international star, whose work has fetched as much as $1.8 million at auction. 

He has always tried to keep his identity a secret, although the Daily Mail newspaper has claimed to have identified him and published a photograph that it said was believed to be him.

Banksy's piece showing a javelin thrower carrying a missile is entitled "Hackney [an East London borough] welcomes the Olympics," while the pole vaulter image is called "Going for Mold," according to a spokeswoman for the artist.

His spokeswoman, of Banksy's Pest Control operation, said the images did exist in the real world, but refused to say where they were. 

More London 2012 coverage from NBCNews.com

A dispute with a London graffiti legend known as King Robbo and perhaps some jealousy at Banksy's success mean some graffiti artists will paint over his work where they can find it, a London street art source told NBCNews.com.

For other street artists, the risk is mainly from the authorities.

Corporate clown lasted six days
An artist known as Mau Mau painted an image of Ronald McDonald with sponsors' names on his costume and an Olympic torch belching out black smoke over the Olympic rings on a wall in Ealing, West London. The local authorities painted over it six days later, he told NBCNews.com, despite the wall belonging to a friend of his.

Mau Mau said he came up with the idea after the Olympic torch relay went past his studio in the Devon area of western England and he "could barely see the torch" because of trucks emblazoned with corporate logos.

"I love to watch sport," Mau Mau said, refusing to give his real name. "I love to see Usain Bolt run the 100 meters … It's lovely to see lots of countries together competing.

"I don't see that as negative at all, it's more the branding side of things. I think it should be run more ethically… it should be more for the people and less about huge corporations," he added.

Leave the big hat! 10 things you can't bring to the Olympics

Teddy Baden, 32, painted the image of one of the Olympic mascots and the overly amorous dog to poke fun at the Olympics in a "non-malicious" way, he said.

"It becomes such a serious thing sometimes," he said, adding that he hoped the image would appeal to the "English sense of humor."

"We always support the underdog in sport, and we can take a pop at things and have a laugh at ourselves ... it's just a bit of fun," he said.

'Welcome to London, it's gray'
Lee Bofkin, co-founder of Global Street Art, which finds walls that artists are allowed to paint and keeps an archive of images, told NBCNews.com that the "vast majority of [street] art has been satirical, sending up the Olympics, noting its heavy-handed corporate presence, and just sort of generally poking fun."

He expressed disappointment that some art had been painted over, citing a wall in Plaistow, East London, a popular spot for street artists that was until recently covered with art.

"A few weeks ago, it was completely painted gray," Bofkin said. "It's a shame. We're saying to tourists 'Welcome to London, it's gray,' rather than 'Welcome to London, it's colorful.'"

The Keep Britain Tidy campaign group once opposed all kinds of graffiti or unauthorized painting on buildings, but no longer.

“What we have a problem with is low-grade ‘tagging,’ that kind of graffiti … that’s just horrible and makes places look unloved,” Helen Bingham, a spokesperson for the group, told NBCNews.com. “We have less of a problem with Banksy-esque street art.”

She said ultimately local people should decide if they wanted an image preserved or removed, but admitted it was a tricky subject.

“One person’s art is another person’s abomination … of all the issues we deal with, it’s the most difficult," Bingham said.

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A nun and a priest stand outside the Monastery of the Cross after it was defaced with graffiti on Tuesday. The monastery, built on the spot where tradition holds the tree from which Jesus' cross was made, was defaced with graffiti bearing the hallmarks of militant Jewish settlers, police said.

JERUSALEM -- A Jerusalem monastery, built on the spot where tradition holds the tree from which Jesus' cross was made, was defaced with graffiti bearing the hallmarks of militant Jewish settlers, police said on Tuesday.

"Death to Christians" was daubed in Hebrew on the outer walls of the Monastery of the Cross, an 11th-century fortress-like holy site situated in a valley overlooked by Israel's parliament.

Army Radio reported that "Maccabees of Migron" was painted on the monastery, too, The Associated Press reported. Maccabees were ancient Jewish heroes, and Migron is an unauthorized settlement facing a court-ordered evacuation. 

Israel: Palestinian deal abandons 'way of peace'

Such acts originally targeted West Bank mosques but have recently expanded to include a mosque inside Israel, Israeli military bases, and now, a Christian holy site.

Police spokesman Micky Rosenfeld said the words "Price Tag" were also painted overnight by the vandals, who damaged two cars parked outside the monastery in the attack, according to Reuters.

The slogan, used by Jewish settlers in vandalism attacks on mosques and Palestinian homes in the occupied West Bank, refers to the retribution they say they will exact for any attempt by the Israeli government to curb settlement in the territory.

Israeli settlement building up 20 percent, watchdog says

"I am a priest and I forgive," Father Claudio of the monastery, which is administered by the Greek Orthodox church, told Reuters.

Rosenfeld said police had opened an investigation.

Reuters and The Associated Press contributed to this report.

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(This report has been updated to correct an error.)

By Andy Eckardt, NBC News

BERLIN – Irmela Mensah-Schramm has embarked on her very personal "combat mission" almost daily for 26 years. Her weapons? A scraper, nail-polish remover, a camera and lots of courage.

Come rain, heatwaves or stormy weather, the 66-year-old sets out to battle what she calls "extremely disturbing" neo-Nazi and racist graffiti, stickers and posters that blight the streets of Germany's capital.

The retired special-needs teacher has now removed more than 90,000 stickers and scribblings.

"Even when I injured my leg several years ago and was walking on crutches, it did not stop me from removing the muck off traffic light poles, bus stops or building walls," Mensah-Schramm says.

Mensah-Schramm travels by commuter train to areas she believes are right-wing strongholds, places where xenophobic propaganda and spray-painted Nazi symbols mix with gang-related graffiti and the more colorful works of spray-paint artists.

'Appalled'
Her "vocation" started with a single neo-Nazi sticker on a street light outside of her apartment in the upmarket Berlin-Wannsee area.

"One morning, I saw a banned Nazi symbol well visible on a lamp post and was appalled that people in my neighborhood ignored it day in and day out, without removing this trash," Mensah-Schramm recalls.

"Only a short while later, I witnessed an incident in which my Indian brother-in-law became the victim of racist bashing. This shocked me so much that I decided to act."

John Macdougall / AFP - Getty Images file

Anti-Nazi activist Irmela Mensah-Schramm scrapes a sticker off a drainpipe in eastern Berlin's Lichtenberg district on December 20.

She documents much of the offensive material in photographs and has compiled a scrapbook, which she always carries with her. Mensah-Schramm calls her project "Hate Destroys".

"For many years, I have been displaying my pictures in exhibits across the country," Mensah-Schramm says. "I talk about my experiences in schools and I regularly host workshops with children and students, generating awareness for the bad impact of these ugly racist messages."

Swastikas
Even ill health hasn't stopped her determined drive to wipe out extremist propaganda. After undergoing a cancer operation at a Berlin hospital in 1995, Mensah-Schramm found two swastikas painted in a stairwell. She rushed back to the nurses, asked for acetone and scrubbed away as much as she could before becoming too weak to finish the job. It was the first day Mensah-Schramm was able to get out of bed.

"In some journeys, I need to take tougher measures with black spray-paint or anti-graffiti solvent to remove writings off walls, and sometimes I even ask people on the street to help me out, if I cannot reach the graffiti," Mensah-Schramm says as she walks past run-down apartment buildings in an economically depressed neighborhood in the Berlin suburb of Koenigs Wusterhausen, which was once part of communist East Germany.

"Look, that is my work," she proudly points out, as she walks past a black square, which was once a swastika that she recently painted over.

Her message is clear: Don't look away.

"You cannot achieve something by doing nothing," explains Mensah-Schramm, whose husband was born in Ghana.

"This type of xenophobic propaganda on the streets can help to spread dangerous ideologies, which can be part of a radicalization process that ultimately can lead to extreme violence," she says, referring to recent revelations about a neo-Nazi terror cell that shocked Germany and led to a nationwide debate about the danger of right-wing extremism in the country.

Murder spree
Two men, Uwe Mundlos and Uwe Boehnhardt, and their 36-year old female accomplice, Beate Zschaepe, formed the so-called National Socialist Underground (NSU). The group is believed to be responsible for the murders of at least nine small businessmen of Turkish and Greek origin between 2000 and 2006, as well as the slaying of a police officer in 2007.

Much to the embarrassment of German authorities, the country's law enforcement agencies only connected the crimes and their xenophobic motives in late 2011 after two of the three cell members committed suicide, following a bank robbery that put police on their trail.

German investigators originally suspected that the victims were most likely killed by fellow immigrants and might have been involved in gang-related crimes.

While critics say that German authorities had turned "blind on the right eye", by focusing instead on tackling Islamist terrorism, lawmakers set up an anti-terror center for right-wing extremism in December. Last month, Germany's parliament also appointed a commission of inquiry into the series of killings.

The German government has also established a database aimed at better coordination in the fight against violent neo-Nazis, partly because the NSU terror cell apparently remained in the shadows for so long due to poor lines of communication between different national security agencies and state authorities.

"Attacks on local politicians and violent acts against foreigners show that the goal is to spread fear and terror," Heinz Fromm, the head of Germany’s domestic intelligence agency, told a recent symposium in Berlin.

'Brutality'
Germany's domestic intelligence agency estimates that there are about 9,500 potentially violent neo-Nazis among the 26,000 right-wing extremists in the country.

"For years, we have been seeing that brutality within right-wing extremism has been on the rise," says Dr. Alexander Eisvogel, vice-president of Germany’s domestic intelligence agency.

• Homes raided after neo-Nazi torchlight parade

However, Mensah-Schramm insists that she remains unafraid.

"I have been threatened many times by neo-Nazis, who have seen me remove their works,” she says. “And once, I came across big letters written on a wall that read: 'Schramm, we will get you'.

"Another time, I found my photo illegally posted on a well-known neo-Nazi website, where the subtitle indicated that nobody would care if I was dead," Mensah-Schramm describes.

She filed an official complaint over the violation of her personal rights. "Unfortunately, that got me nowhere because the server for the page was based in the United States," Mensah-Schramm says.

Andy Eckardt, NBC News

This neo-Nazi sticker that reads "nationalism" in German is among the thousands that have been removed by Irmela Mensah-Schramm.

In fact, German authorities are facing a growing challenge when it comes to online enforcement.

Extremist groups are turning to web servers in the United States to host their content and spread their messages beyond the jurisdiction of local authorities. While displaying of Nazi symbols and the incitement of racial hatred are outlawed in Germany, neo-Nazi websites take advantage of free speech laws in the United States.

As the retiree counts sticker number 70,076, removed at a bus stop outside a local high school, she turns and says, "There are these small, but very rewarding moments."

"A former neo-Nazi, who had massively threatened me in the past and later exited the scene, stopped me on the street one day," Mensah-Schramm says with a choked voice. "He took off his sunglasses, looked me straight in the eyes and said that he wanted to thank me for never giving up my fight.

"I was so overwhelmed by the gesture that I started to cry," Mensah-Schramm says, before walking off to complete her mission of the day.