Chicago officials Wednesday threatened IBM with $50 fines for each of 100 ads that were spray-painted on city sidewalks.
The computer company said it has halted the campaign, which was handled by Ogilvy & Mather.
Symbols of penguins, hearts and peace signs began appearing on Chicago sidewalks last week as part of "Peace, Love and Linux,'' the ad campaign for IBM's Linux computer operating system.
A spokeswoman said the city's Streets and Sanitation Department did not know whether IBM was directly involved in the campaign. Proceeds of any fines would pay to clean up the graffiti -- an effort the city says will cost $134 an hour for equipment, labor and supplies.
IBM said the sidewalk campaign in Chicago was supposed to be done with chalk, not paint.
A similar marketing campaign used biodegradable paint on San Francisco sidewalks before it was stopped last week.