I've been hassled a number of times. In my experience, it seems the less "official" a person is, the more likely they are to cause problems for me. Rent-a-cops, and transit cops have been the worst. City cops have been better. Federal police have been no problem. Off the top of my head: Downtown Houston, a rent-a-cop threatened to take away my equipment at Enterprise Plaza. I told him that I'd be happy to call 911 so a police office could explain the law to him. He backed off. Downtown Long Beach, California a transit cop demanded to see my permit. I explained the law to her, and she was happy. I preceded it with, "I've been doing this for 10 years -- it's my job to know what I can and cannot do." Downtown Chicago (Printer's Row area) -- Chicago cops asked what I was taking pictures of and why, but didn't make any threats. Downtown Hong Kong (Admiralty) - Chinese military police didn't give a crap about me shooting their barracks. Downtown Hong Kong (ifc Center) - Rent-a-cops were curious about me, but being a white guy, they were afraid to approach. When it appeared to me they were getting concerned (a sudden burst of radio use), I walked over to them and asked them where they thought the best locations would be to take pictures. They loved this, and pulled out a map that they drew on and let me take with me. Downtown Bellevue, Washington - Cops walking by stopped in their tracks and got out of my way so I could take a shot! Holy crap! Downtown Washington, DC - Taking pictures of various government buildings at 3am - United States Park Police would cruise by me every couple of minutes on a scooter, but didn't interfere. I think he was just making sure I wasn't spray painting anything. When I was working for a large media company, our photographers were threatened all the time. The lawyers at corporate had a set of guidelines for the photographers. Among the more interesting points - Never give up your media. If a cop demands it, tell them they need a judge's order or a search warrant, and to submit it to the company's lawyers for consideration. - Never erase pictures you've taken. If a police officer believes you've committed a crime by taking pictures, erasing the photos is destruction of evidence. A police office cannot compel you to commit a crime. When I had my old Sony camera, it had two media bays. I always thought that if I ended up in a situation where a cop demanded my film, I'd just pop out and hand him the empty card. Sadly, I never got the chance. My new strategy is to shoot on MicroSD cards, and if I'm in a bad situation, I'll just swallow it.