Sony has caused outrage with a guerrilla marketing campaign for its PlayStation Portable (PSP) handheld gaming platform.

The company hired graffiti artists to daub pictures of children playing with PSP consoles on cities across the US. But the campaign has run into trouble after complaints that the advertisements break anti-graffiti ordinances. 

Pedro Ramos, 'managing director' of Philadelphia, one of the affected cities, has sent a cease-and-desist letter to Sony, and has stated that he will be fining the company for violating city laws. He has ordered Sony to remove the paintings.

The campaign in Philadelphia has also been slammed by the Society Created to Reduce Urban Blight (Scrub), an activist group that fights illegal outdoor advertising and graffiti in the city. 

"Scrub believes that this renegade campaign is not about art, but about arrogance and greed," said the group in a statement. "Sony is violating Philadelphia sign laws and disrespecting its neighbourhoods."

The advertising campaign is running in seven American cities, including Los Angeles, San Francisco, New York, Atlanta and Philadelphia. Adverts in San Francisco have already been defaced with comments like 'Fony' and 'Get out of my city'. 

This is not the first time a technology company has got into trouble for graffiti. In 2001, IBM was forced to pay more than $120,000 in fines and clean-up costs after its advertising agency spray-painted Linux advertisements on pavements in Chicago and San Francisco.