I hate that our society is more and more dependent on legal action against every single perceived wrongdoing. Run to the government at every little thing that offends you, and let the police handle it. Is there a safety issue here? I don't know, as I haven't seen the video. But your first response was to spend time figuring out exactly where this guy was flying, assume from an email address what his intentions were, and then spend time chatting to the FSDO and airport about this "safety hazard?" Why not shoot the guy an email and tell him your concerns. He may not even know there's an airport nearby, and you could point him towards some online resources to help him out in the future. When people ask me where I fly, they often respond with, "Really? I didn't even know ________ had an airport!" Instead of educating the guy, he may now be facing legal action (I doubt anyone will pursue this, but still.)
We have so many laws on the books that you can't go a day without inadvertently violating one, and it's partly because of busy-bodies like the OP. It's also partly caused by people like the OP describes who do stupid, possibly dangerous, things either knowingly or unknowingly. It's all fun and games 'til someone gets hurt. After that, we get more and more laws.
Most people in my community store worthless crap in their garage, and leave their $30K vehicles parked in the driveway. The driveways are kind of small, so most people end up partially or completely blocking the sidewalk. Besides being annoying to have to walk around cars every other driveway, it could be unsafe as it forces people to walk into the street. Oh, it's also illegal. I've never called the cops on any of these folks, but I have mentioned it to them when I see the owners out when I'm on a walk. Virtually every single person has responded with a genuine, "Thanks, I had no idea!" and after that friendly chat, they keep their cars pulled up out of the sidewalk. See how that works? No cops needed. Sure there will be people who just don't care, and the cops may need to eventually address the issue with a few folks, but for the most part problems can be resolved without getting law enforcement involved.