Police in Tampa, Florida, have a new weapon in the fight against crime - a video camera. Police use video cameras to scan public areas in Tampa's entertainment district to look for wanted criminals. But a backlash is developing among critics who contend that using such high-tech surveillance techniques in public is an invasion of privacy.

The Tampa system includes 36 surveillance cameras that scan the crowds in the city's popular Ybor City entertainment area.

Officers monitor the video feed in a command center using sophisticated face-recognition technology that seeks to match a face in the crowd with the photo of a wanted criminal.

Police in Tampa and other cities that are considering the technology are excited by its potential.

Richard Chace is Executive Director of the Security Industry Association, a group that promotes the use of face recognition technology and closed circuit television systems by law enforcement and private industry. He said "this technology is about public safety and life safety. It is an invaluable tool for law enforcement to ensure that we have safe communities in which we all raise our families," said Mr. Chace.

The new face-recognition technology was developed by a New Jersey company, Visionics Corporation. Visionics Chairman Joseph Atick says the face-recognition system is the high-tech equivalent of a policeman recognizing a suspect while walking down the street. "It does not record any images of people that it has seen in front of any of the video cameras unless a match is established with a known criminal," he said. "With responsible use, it does not invade the privacy of anyone except the criminals."

But there are plenty of critics who contend that the face-recognition technology is an open invitation to abuse by police departments and governments.

Jeffrey Rosen is a professor at George Washington University Law School in Washington and the author of a book about what he regards as intrusive new technologies. He describes the new technology as "a threat to privacy when we have no spaces in public where we can go without being observed."

In Professor Rosen's view, some of the new technology represents the potential for abuse, whether it is scanning a crowd for criminal suspects or photographing the license plates of drivers who speed or go through stoplights. "Freedom to engage in low-level disorder is something we generally take for granted, and it could be a concern if we live in a zero-tolerance society where every single wrongdoing is picked up by cameras and automatically punished, we might feel a little bit less free," said Mr. Rosen.

Supporters of the face-recognition technology say it has helped to reduce crime by 40 percent in one high-crime area of London. Joseph Atick says the placement of 300 cameras around the five main shopping areas have resulted in 20,000 fewer criminal incidents over a two-year period.

"In human terms, this translates into at least 20,000 less victims," said the Visionics Corporation chairman. "Yes, 20,000 human beings have been spared the pain and humiliation of crime. How do you put a value on that?"

But opponents remain unconvinced and vow to challenge the new monitoring systems in court. "It would be useful right now for us to study the experience of England in some detail," said Professor Rosen, to "see about the benefits as well as the costs of the cameras and then just make a decision as a country about whether we want to go down that road. We face a really dramatic choice about whether we want to increasingly succumb to a surveillance society or whether we think that the costs are not worth the benefits and I think that is a public debate we have to start having."

Supporters and critics of the new technology do agree on one thing they both believe that Congress must enact stringent guidelines on the use of such equipment to minimize any threats to privacy.