Visit the direct link above or go to: http://www.filestube.com/account/settings/account.html and click ‘delete account’ if that does not work.
We wonder, however, because of the nature of FilesTube, what happens to your email address information, since you accepted their terms (which basically allows them to use your email address for spamming).
URLS:
http://www.filestube.com/account/delete_confirm.html