You use phpbb?
read this:
http://www.phpbb.com/phpBB/viewtopic.php?t=234090
These hacks might be useful:
http://www.phpbbhacks.com/download/2959 - Deter Spam Websites
http://www.phpbbhacks.com/download/560 - Anti Robotic Registration Flood
http://www.phpbbhacks.com/download/1528 - Hide Unactive Members
http://www.phpbbhacks.com/download/2961 - Block Open Proxy Registrants
http://www.phpbbhacks.com/download/2975 - Log Registration IP
http://www.phpbbhacks.com/download/3182 - Block Bad Bots
http://www.phpbb.com/files/mods/disa...bots-1.0.1.mod
There's also a hack to make it so members cant get their homepage shown before they did certain amount of posts. I havent the link for it, but search for it. Its out there somewhere.
Further you can also remove the homepage option in the signup and user modify templates. You can still add homepage in control panel for trusted users, if you do it that way.
Also you can remove the "newest member" from your mainsite.
Im pretty sure you can get a hack soon for the "nofollow" tag too
