Well temporary ban is a better solution. To be honest I have tasted it

and was really sour.
I got banned twice first one was of 14 days but the next one was 60 days. So you see if you continue out there to spam it keeps on increasing with some kinda multipliers I guess which I think is the best punishment ever for spammers here.
It is not sufficient. You might be an example of a person who has improved (I haven't looked into you), but most don't. Also a lot of spammers have additional accounts from where they spam. We are not talking about replacing temporary bans but rather adding a removal of the signature to it. It could be pretty simple if implemented in the new forum
As for the topic at hand I believe, a change in feedback system/the trust system as we know it to include sig spammers would be more feasible and effective than banning one's signature. Correct me if I'm wrong.
As in what? Community members leaving opinions about other users (aside from a trust score)?
You up for a challenge?

, running one with sho currently could easily take another one.
