Blocking Spammers

My new Elgg social network (SimplyFair.net) was hit by spammers this morning. They erased my members and put 10 of their own in instead. Two of them were active when I went to the site, which was really spooky. My developer was able to erase them and restore my members. But she's asked me to consult with you folks to see if there are plugins or other means of combatting this menace. Would appreciate your help. 

My developer says her company's servers are being hit regularly by spammers, apparently from China. Looks like they think they can have a field day with social networks here. We're going to be adding a captcha to our site. But are there other resorts?

Feedback and Planning

Feedback and Planning

Discussions about the past, present, and future of Elgg and this community site.