Signature link - Good or bad !!!

[Susmita]

Should I allow people to add there site url in their signature link? As I have found that, with many good site links lot bad links are also coexisting. Some of them are porn site, some of them are spammers. I know marketing him/her self is everyone's right. But should I allow people to use forum as a marketing base. How negetivity can be wiped out from these popular marketing base.

If I disallow people to use their links in their signature, is there any possibility to loose my forums popularity?

What should I do? Should I add nospam with the url or no follow tag to the forum urls.

Or how can I turn the negetive factors associated with the signature link as a positive one?

[ctabuk]

I have just cleared out my own forum, got rid of all dead posters etc etc - If you dictate about letting users use their URL's or not, then you are doomed before you even start. We need our URL's in forums to help with our SE prescence