Automatic account association is something that allot of websites are doing (google logons etc another example would be wordpress sites and logons) and very dangerously in my opinion, sometimes when you resolve tech problems for other people if your not careful the website tries to auto associate a client account with the person supporting them’s private accounts/logins, leaving you with the problem of trying to separate such automatic associations which can be completely inappropriate, again automatic tends to work only for the norm use model.