More worrisome, the report's authors say, is the possibility that government monitors may integrate facial-recognition and other technologies to develop databases that track individual behaviors.
"Surrendering privacy does not make us safer," said Kevin Keenan, executive director of the ACLU of San Diego and Imperial counties, which produced the study with ACLU chapters in Los Angeles and San Francisco.
Titled "Under the Watchful Eye," the 25-page report examines privacy and civil liberties, and concludes that public surveillance programs should be stopped until they are thoroughly evaluated.
Widespread surveillance violates the constitutional protections against unlawful search and seizure without a warrant or probable cause, the report says.
The ACLU began examining the use of cameras by local governments after a two-camera pilot program in San Francisco in 2005 grew into a larger project that still is expanding.
San Francisco officials conceded that they had done little evaluation of the cameras' effectiveness in preventing crime. According to the ACLU report, the only records the city could provide showed that crime increased in more than half of the areas under surveillance.
More California cities are using surveillance programs in an effort to suppress crime.
ACLU researchers surveyed 131 jurisdictions and found 37 communities with some type of video program. Of those, none had undertaken a comprehensive evaluation of the cameras' effectiveness. Eleven police agencies enacted policies to regulate use of the systems.
Grants from the U.S. Department of Homeland Security pay for many of the programs.
Last fall, the El Cajon, Calif., Police Department used federal funds to buy a "sky watch" mobile tower to monitor crowds. It was first used at a large retail shopping mall.
"We're excited about the possibilities," El Cajon police Capt. Pat Sprecco said at the time.
Government officials have an obligation to fight crime and terrorism, said Keenan of the ACLU, but they also need to be smart about how they use their limited resources.
"We should be concerned that this is an ineffective way to do law enforcement and spend taxpayer money," Keenan said. "We should be concerned about the growth of a total-surveillance society."
The ACLU report said surveillance is helpful in strategic places, such as airports, but has less practical value in general meeting spaces.
San Diego County is well-represented in the number of cities that use surveillance cameras as a law enforcement tool.
National City spent $60,000 in Homeland Security money on a system last year.
Four cameras began monitoring a stretch of Roosevelt Avenue in July 2006 to help fight prostitution. City Manager Chris Zapata said policies were put in place to prevent abuse of the images.
National City police are expected to report to the City Council in November on the cameras' effectiveness, Zapata said. In the meantime, he said he feels the area has improved by a "quantum leap" since the cameras were installed.
The Metropolitan Transit System has mounted cameras at several trolley stops in Chula Vista and San Diego.
San Diego has cameras that look at a recreation center and adjoining park.
"A lot of criminals are bothered by cameras," San Diego police Sgt. Alan Hayward said. "If they do have a crime there, at least we can look at the film and see if we can identify the suspects."
The city uses mobile cameras for security at major events, such as the Super Bowl or political demonstrations.
In Vista, the Sheriff's Department uses a mobile camera system it bought with a $20,000 federal grant.
Beth Givens of the Privacy Rights Clearinghouse, a San Diego organization that advocates on behalf of consumers and their personal information, said she has been worried about government surveillance for years.
"Government agencies do not have a clean record when it comes to surveillance abuses, going back decades," Givens said. "Without strong policies and effective oversight, it's a given that abuse will occur."
Tracking scenario
San Diego State University sociologist Philip Gay said the rising use of video surveillance is troubling because no clear definition exists of what purpose the cameras serve.
"This is a huge problem," Gay said. "Today, you don't know when you're being observed, why you're being observed, what's being done with the information or whether the information is being edited."
One scenario outlined in the ACLU's report has government agents employing video surveillance and other identifying technology to track people's activities.
Technology could be used to create files that detail where individuals shop, what they purchase, whom they visit and how they spend time.
The potential for abuse of information like that may be limitless, experts say. Insurance companies, business rivals or corrupt authorities might exploit such data.
Keenan said the ACLU will provide copies of its findings to elected officials across California in an effort to jump-start public debate on the merits of such video programs.
Correspondent Pauline Repard and library researcher Denise Davidson contributed to this report.
