I started wondering about this about 15 minutes ago.
The purpose of signature spam is to trick search engines. Search engines look at both how many sites link to a target and what words are used in link text. If I post a link that says reliable cars that points to Toyota's web site, then search engines may be more likely to bring up toyota.com when people search for toyota.com.
I was wondering if it would make sense if rather than deleting such signatures such signatures were changed to attract the wrong type of attention.
For example, if a user posts a link that says
maybe it would make sense to change that to
Those links point to the same site.
Right now, locking or deleting spam accounts doesn't do much to deter future attempts by the same spammers.
But if posting on your site would actually create a number of *undesirable* links to their spam site, might a spammer be more likely to avoid your site in the future?