BDA is Big Dick Anon. A very controversial character who posts on 4chan now and then.
In high probability, a LARP, but in my case, I've known people like that. People put in witness protection, from my POV, way out in the sticks where I lived once.
Here's a site that tracks his posts:
https://paulfurber.net/bda/
Take a lot of salt with you when you go. Cheap entertainment, at the very least. Site linked has the links to the half threads in the top right corner of each BDA entry.