These sort of actions always seem to me like, "See, I was able to enter your home at night and punch you in the face. Now you know how bad your police are at defending you. I'm making you aware of this for your own good."
More like "See, I was able to enter your house. Now I'm going to mail a copy of the key to thousands if not millions of people. Oh, and since you probably use the same key for your house, office, and car, they'll also have access to those. But it's not my fault. It's the government's."
They didn't just choose anyplace, though. They specifically chose the mybart site because of the BART's recent actions. They even say this on the page. That is very different.
Gee. Thanks.