See more @ http://samy.pl/evercookie/ Anyone can easily change their IP address and delete their session cookies, something that allows banned members to easily re-register. It'd be awesome if evercookie gets implemented somehow in xenforo. An add-on would also do nice I suppose. Test it by yourselves. You can even change your browser. It can still detect you I have just suggested g0rn, the creator of Multiple Account Detection add-on, to use evercookie with his last add-on.