Most network servers record the web sites visited by each terminal. Government usually have additional software to serve their own tracking needs. I'm not technical enough to know whether a network server's records could trace back to an individual post on a bulletin board.
Most ISP's also record sites visited by each of their subscribers.
Web sites record the IP address of each visitor and in the case of bulletin boards (Civilair Forum, PPRuNe Forum etc), attach the user's IP address to the post.
Nothing new - that has always been the case.