Currently, if any anonymous user is considered to own all anonymous comments when it comes to the ability to edit or delete them.
I think this is wrong for two reasons:

• That user is then able to delete comments made by other users even when they only have the "can delete own comments" permission (and ditto for edit).
• This means that anonymous users have some privileges that logged in users don't have.
  A user could edit a comment. Log in, and then no longer be able to edit it. Fairly bizarre.