I see this suggestion a lot. How would you propose going about doing it? Who is account farming and who is just an occasional and crappy poster?

If account sales were banned on here, they'd simply move to another website and carry on there.

As a thought experiment perhaps all sigs should be shut down for a week or a month just to see how it impacts the forum overall. If enough people realise that prospect is permanent if the tsunami of crap continues, maybe they'd start to shape up.