Thanks for this. I think it would be good to explicitly state some rules for signatures in http://forum.xda-developers.com/announcement.php?a=81
so that there's no argument.
Also, it would be great if it was possible to hide signatures from particular users. I know we can hide all signatures, and I know we can ignore individual users, but I'm asking for the ability to hide signatures from just some users, while still seeing the rest of their post. Bonus points if this could be further finessed into a choice between "Hide this particular signature from this user" (which would cause the signature to be unhidden if the user edited it) and "Hide all future signatures from this user".