Can't stop the spammers!

[readjono]

No method on vBulletin's anti-spam features seems to stop them. They register and add links to their signature :(

[Dismounted]

If they are registering, it may indicate that a real person does the CAPTCHA/Q&A, and there is nothing you can do to stop that.

[veenuisthebest]

In usergroup manager under Signature Permissions

Allow Link BB Code->Set to NO
Allow HTML BB Code->Set to NO
Allow HTML->Set to NO