If a user has x amount of rep, or a badge, that person can flag any dubious first post, the suspected spammer and its post/s get sent to the corner.
The newb gets limited to a hidden forum, and mods give a thumbs down later.
That could backfire because rep can be gamed up reasonably high by a bot account (for example, the rep bonuses for views to profile), and if there are no post limits, and only low rep users can be 'crowd-modded', bots could very quickly escape 'rep hell' by gaming views/posting rapidly.
If this was done, the rep level req for users to ban posts would have to be very high (at least 5000, maybe 10,000) to curtail abuse.
I think it's a bad idea because if there is an exploit in the rep/badge system anywhere, spammers could start banning legit topics.
This. Tom, where oh where are you...