The administrators of Bluelight reserve the right to delete any and all data associated with abandoned accounts including, but not limited to: any posts made by the user; any blog entries made by the user; profile information entered by the user. Further, Bluelight reserves the right to reissue the username associated with an abandoned account.
An account is deemed to be abandoned if the account has zero posts and the user has no activity in the last three months or if the account is a 'Greenlighter/Bluelighter' with at least one post and the user has no activity in the last six months.
This is our current approach to the issue, which sounds about like what you were suggesting.