It's not in anyway tied to a My Wallet account. All I did was write a quick spider to check the signatures on bitcointalk and create a tag for each one found. I can remove your signature if you like, however remember if blockchain can index them then any entity (with possibly more nefarious intentions) can also. I guess just be careful posting your bitcoin address publicly. Also be aware not only about information you may have revealed yourself but also also of information that people you have sent and received transactions from have also made public.

Tagging does not follow coins. However this is probably possible by determining the change output and attaching a confidence rating.