The problem is of course that I have no issue with any or some user linking back to their site.
A spam sig is simply someone who got paid to post to go through sites and post on topic and have links to certain keywords - and they usually link to the same site twice. As a human it's quite easy to spot them.
I think I have decided to manually review the reported cases and just deal with it.
Our new signature rules might include:
No SEO keyword spamming.
No linking to 'download or share' sites.
No dupe linking, one link to remote site is enough.
If we 'suspect' someone from link spamming, we're free to edit their signature.
What do you guys think about this?