A picture may be worth a thousands words, but if the photo is of a police officer's personal car parked illegally, you may need some of those words to talk your way out of a pair of handcuffs.Three people said recently police detained them for nothing more than taking pictures on public, New York City sidewalks.It happened to Jan Lee. The Chinatown businessman, frustrated by city employees parking illegally in front of his antique store on Mott Street, decided to start documenting the abuses.Lee used his digital camera to snap photos of the most egregious violators -- cops who parked their personal cars at fire hydrants. While taking one such picture, Lee said he was grabbed by a plain-clothes NYPD detective and forced to walk to police headquarters.Lee has more than just his story -- he has photos and video to prove it.Just before the detective handcuffed Lee behind his back, the quick-thinking businessman switched his digital camera to movie mode and started recording. The video captured the conversation as the detective called for back-up units and told other officers why Lee was being detained."This guy's taking pictures of cars with police plaques, right? He's taking pictures of a whole bunch of cars down the line," the detective said.Lee said police released him without charges and returned his camera without apology about 20 minutes after he was forced to kneel with his hands cuffed behind his back on Park Row. Lee said it was embarrassing to be arrested in front of his neighbors, especially because he had done nothing wrong.Inquiries to the NYPD revealed the department has no record Lee was ever detained. However, he said the commander of Chinatown's 5th Precinct stopped by Lee's antique store to make amends.Two volunteers from a non-profit transportation study group were also detained by the 5th Precinct earlier this year. The college students were conducting a survey of illegal parking in Chinatown for Transportation Alternatives. They said they were nabbed when they snapped photos of illegally parked private cars belonging to police officers. According to the students, police cited the Patriot Act and warned them they could be held indefinitely without charges. Officers allegedly offered to release the volunteers immediately if they agreed to erase photographs of the police officers' personal cars. They complied and were released.There is no law barring citizens from taking photographs on public sidewalks. Officers can stop people only upon "reasonable suspicion" of a crime. Since taking photographs is not illegal, these stops would seem on the surface to violate the First and Fourth Amendments to the U.S. Constitution, and common sense.