I have to agree that although I've seen a lot of divers with cheap cameras touch in places they shouldn't, the worst "reef killers" I've ever seen was a group of NJ divers on a NW Bahamas Nekton cruise we did a few years ago. Not only did the group have some of the largest and most expensive camera gear I've ever seen (the rigs were so heavy that they needed pool floaties on the arms of the strobes!), but they LAID ALL OVER the reef to get the shots they wanted. They were the rudest bunch of divers I've ever seen in my life, shoving other divers out of the way to get the shots they wanted, and destroying the reef with their entire bodies and fins wherever they went. It was unreal.
One of my favorite incidents aboard Nekton was with one of these NJ UW photographers on the NW Bahamas itinerary (this was in 1998). I continually warned one of these photographers about destroying the reef while he was trying to capture a good shot. He disregarded my warnings, and on the last day we were diving The Strip, off Bimini. He decided to lay on this very narrow reef to get a picture of a scorpionfish. What he didn't realize was that he was laying on top a hole that contained a large green moray. He got bitten on his stomach, and while the injury was realtively minor, it scared the crap out him (literally--I was glad I didn't have to clean out his wetsuit!). I never wish for anyone to be injured when diving, but in this case justice was served.