Yeah. I guess staff will have to do an IP scan in case, since another member got (re?-)banned recently. Not to mention it could easily be someone who's friend with another member here who saw him browse the forums and decided to annoy him there.
Also I know some of you invite people on the forums, sometimes, but didn't check the thread in the comments/suggestion section regarding that. From experience, IRL people acts differently online, so if you invite friends, they might just troll the board or the IRC channel. You gotta be careful about that. At least warn them to play nice when they join and avoid inviting people who have absolutely no interest with calcs or our other topics.