Los Angeles, California:  With municipal budgets already strained, the City of Los Angeles spends millions of tax-payer dollars every year to clean up graffiti.

The specific numbers are hard to pin down, but over 30,000 graffiti reports are received by the LA Office of Community Beautification per month.

LA County reportedly spent $30 million dollars abating graffiti in 2007.  

Chicag, Illinois - Five additional graffiti abatement officers were hired by the City of Chicago's Graffiti Blasters to combat graffiti.  An additional 7,400 tags have been removed since the hiring of the new crew.  Graffiti Blaster was started in 1993 by Mayor Daley to address the graffiti problem.

More at ABC7 News Chicago

SAN JOSE, California – In 2011, a city-run graffiti removal program was outsourced to a private contractor.  The move has been mostly praised by city leaders and community members.  
 
As graffiti has been more quickly and effectively removed from the neighborhoods, the graffiti taggers have shifted their targets to freeways and rail bridges where reaction time from Caltrans and Union Pacific is slower. The result is that graffiti tags remain for extended period of time in high visibility locations.

Total number of graffiti tags remains constant at 3,600 but the incidents within the neighborhoods has decreased.  City officials credit quick response times, triaging graffiti incidents, and matching over paint to background color. 

City officials say that total square footage of graffiti is down by approximately 25% since the previous year.

City officials reported that 87 percent of reported graffiti is cleaned up within 24 hours and 96 percent within 48 hours.
 
A smartphone application allows residents to report graffiti and then is emailed a response once the tag has been removed, showing the before and after photos.  High satisfaction rates are reported from residents who have used the system.

Link to Mercury News for more details.