Checking IP address before final registration???
After seeing so many threads on point hunters...i cant help wonder why cant we have a mechanism to check for IP address just before the final registration process and if the IP address already exists...then the user be prompted with a mssgs that our record shows an id already exists with ur ip..and be redirected to forgot password screen..
or just a threat message on the sign up screen.."if we encounter mulitiple(pseudo) account logins we shall permanently ban the ip address" should do the trick to some extent.
lastly, i have heard of VBulletin software which addresses similar issues...(especially with regards to shared network and AOL users)