Opinions on graffiti are as diverse as the designs themselves, which either blight or brighten city walls the world over, depending on how you view them.
The issue could not be more topical than in the Italian capital, Rome, where no less a person than the prime minister has immersed himself in the debate.
In language as colourful as some of the sprayed daubings, Silvio Berlusconi described Italy's capital as "dirty" and "disfigured" by the graffiti.
Admittedly, Mr Berlusconi was making as much a political point as an aesthetic one, blaming the left for the sorry state of some of Rome's walls.
But there are many people living here, or visiting this ancient city, who would agree.
"I hate it," said Reuben McQueen, a shop owner in the central historical area.
"Look what they've just done," said Mr McQueen, pointing to freshly sprayed graffiti on the window of his shoe-shop.
"It looks disgusting for the visitors to see this."
Irritation or inspiration?
Anne, an Australian tourist, was also upset to see the myriad lines, designs and general grime associated with the graffiti.
Many argue the graffiti disfigures historic Rome's streets
"I can't believe it," she said. "Especially in central Rome which is so historic. It's a real disappointment."
One estimate suggests there may be as many as 3,500 graffiti artists working in Rome - about 1,000 of them being so-called taggers who spray public buildings and walls.
The ancient city centre, which is a Unesco World Heritage Site, is home to some of the most stunning monuments and architecture to be found anywhere in the world.
From the Trevi Fountain to the Coliseum, from the Pantheon to Bernini's Four Rivers creation in Piazza Navona, it has a rich fabric of history that many believe is gradually being unpicked by the sprayers.
Giovanni Fiscon, the man in charge of a graffiti clean-up operation on the city's streets, said he had a squad of 16 people working in shifts 24 hours a day.
"We're just the emergency team, who try to get to the worst of the graffiti as soon as it appears," he said. "When I see it, it breaks my heart."
The city has a longer-term solution underway.
It has set aside some six miles (10km) of walls for the graffiti artists to use.
I used to spray on public buildings, like the taggers do now, but I realised that wasn't right
Paolo, graffiti artist
Paolo, whom I met spraying paint on one of the designated walls, said he had been a graffiti artist for 14 years.
He showed me his book of hand-drawn pictures, in which he practises sketches of his images before they end up on walls. They were accomplished pieces of art.
"I used to spray on public buildings, like the taggers do now," he said. "But I realised that wasn't right."
Paolo explained that with tagging, you have to rush because the police or someone else could come along at any time.
"That's why so much city centre graffiti is of such poor quality," he added. "You don't have time to do beautiful designs that people might appreciate."
The general standard of artwork had declined since his early days, Paolo said.
He added that much of it was pure vandalism and that is what had turned people off graffiti, because they were not seeing the best of it.
I asked him what he thought of these "official" graffiti walls.
"They're fine, though there is not the same adrenalin rush you get when you are doing it on real buildings and walls," he said.
When you cast your eye along the authorised walls being used by Paolo and his colleagues, you can see why some graffiti has now transferred from the street to art galleries.
But not everyone is convinced.
Italy gave the world the word 'graffiti', but it does not always like to be reminded what that can mean
Franco Ferrarotti, a sociologist who has studied the urban existence of young people, is not impressed by the defacing of Rome.
"It is a pathetic attempt to emerge, to be visible," he said. "I connect it with a sad destiny of a whole generation of young people who cannot find a job."
One famous book on the subject of graffiti is entitled Vandals and Crusaders.
It depicts the street sprayers as modern artists whose work needs to be appreciated as much as conventional imagery committed to canvas.
But is it mainstream, or merely a maintenance headache?
The best graffiti sells for thousands of dollars; the rest, like those on many Roman walls, seems alien in such beautiful surroundings.
Italy gave the world the word "graffiti", but it does not always like to be reminded what that can mean.
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