That is a very interesting story. Perhaps your area is one of the few that has an ordinance that goes around the supreme court ruling that items in dumpsters are now abandoned property. More than likely, there is more to the story and wherever he was diving wasn't legal. He could have been tresspassing, it could have been a recycling bin that was actually owned by someone who was recycling those old computer parts, etc. Maybe it was a construction site where those materials were out for recycling. Anecdotal stories like this always have more to them, and I'm sure there is a reason that the cops took a tip from a teenager and rammed through a door as a result lol. Don't forget the search warrant that would have been necessary, and the probable cause to get said search warrant...more to the story for sure. Interesting that the thousands of people showing their faces in youtube dumpster dives haven't had this issue, nor the ones pulled over by cops in said videos.
Funny story...I was getting my packing material out of a dumpster once when a cop pulled up and asked me what I was doing. Now, dumping stuff in is illegal, so maybe he thought I was doing that. When I explained that I was getting bubble wrap and boxes for packing material, he actually told me that a bunch of the firefighters were dumpster divers and told me other good places to look lol. Like I said, call the police in your area first if you're not sure it's legal.