How to get rid of spam in the groups section of Buddypress


I'm using Akismet and WPMU Anti-Splog to protect against spam. Nevertheless, and even though I just let my site open when I have to test some feature (the site hasn't been launched yet), I've detected 40 groups created that really look like spam -stuff like "lose weight now" and such.

So, how do I protect my site against it?