I start my activity on these pages by pointing to a security problem we have here. I found it when viewing one of my comments to a news article where a new comment appeared:
http://www.science20.com/comments/24095/Re_2009_Peer_Review_Survey_Issue...
I thus wrote there this, which indeed is unfortunately true:
The comment by Tiffany is a spam. It only says "Nice" but points to some shop with cheap bracelets. Tiffany should be removed and then one can remove also this comment.

I would think that it should not be possible to insert a link into the signature.

This is opening this site to miscreants who could link us to phishing sites. This should be fixed!

My warning appears as
http://www.science20.com/comments/24110/comment_Tiffany
and it should really be fixed. If people want to link to their pages, they must have account here.