Sorry to say but I rarely go in there as I am fortunate enough to be able to watch most games live, I can appreciate that for those who rely on their computers for up to date results such feckwittery is a real pain though. I'm not likely to go trawling back through 16 pages plus of a match day thread after the fact though so the idiots do largely get away with it unless you can point out their offences.
Best bet for all concerned is to use the report post function anyone cocking about in there. Posting GOAL!!!!! when there wasn't one and the likes are definite cause for a permenant exclusion from the matchday forum. Excessive negativity is a harder one to call but we can dish out infractions when they go OTT and repeated offenders will then earn short holidays from the forum and stand out more when we consider them for permenant bans.