BuddyPress.org

Allowing users to report spam would be a very useful feature. There’s only so much you can do in terms of technical spam prevention, and technical spam prevention always gets cracked eventually.

If the amount of spam reports for a certain account exceeds x, then freeze the account until an admin can review the account. The admin should then have the option to do an IP based ban of the account if it appears to be a spammer. Some very basic IP based messaging/commenting/posting rate limitation would help too.