I agree with both you guys. Besides the decline in milsurps, etc., face book took a big toll on the forums. I still remember when e-mail lists were the thing. And before that, there were 2, count 'em 2, forums on the internet, then called DARPAnet. One in Mississippi and one at MIT. You had to TELNET to them once you connected into the net on a dialup through a local university.
And, yeah, the feds (all of them) don't need logins to see the forums, but I think it makes it easier for them. Maybe not. FYI, I knew a guy that ran a department at AT&T back in the 80's. As a clue into his responsibility level: His budget for his department was $6 million. A month. He told me back then that all conversations could be "recreated." That is, played back. It was all digital then, and all stored.