There’s a fairly simple and foolproof method to automate spammer deletion. It’s easier to let them in and then delete them automatically than to try to stop them from registering in the first place. Otherwise it becomes an ‘arms race’ type of thing, as well as a game of keep-up-with-BP/WPMU-changes if you try to integrate it.
See it in action at http://visarus.co.uk/bp-spambusher.php – every time you visit that page you will be cleaning up spam registrations for me 
I can put it on CRON if I want but I enjoy the satisfaction of seeing how many registrations I’ve deleted 
40 in the last 24 hours.
Now… my spambusher script gives me some very rudimentary statistics… and in the 2 days and 9 hours since that post above, the number of spam registrations has gone up 50%… but the number that I actually delete myself has gone down by about the same number 
Which tells me two things:
1. People or bots are actually following the link above and tripping the spambush
2. Links to buddypress sites from buddypress.org are just ASKING to be spammed
I found this tips and guide.
Kill and remove buddypress spam registration
It works perfectly
Hi all,
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Thanks,
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info@swipeads.co
I’ve been reading these forums for weeks trying to find a solution to all the spam registrations I’m getting on my site. Keep in mind that I haven’t opened it to the public yet. It is closed and the registrations are closed, but still they are getting in and creating accounts. I decided to do some troubleshooting to see where they are getting in and this is what I found out so far:
1. When I close registration still they get in and create member accounts and Groups in which they inject their spam. 2. I started to turn off some of the buddypress features one at a time, such as the forums and the groups, and the registrations stopped. It’s been several days without spam registrations. I turned on open registrations and still there’s no registration. I turned on Forums and now they are coming back.
Conclusion: they must be getting through the forum, since I understand, uses a version of BBPress. Now I have to get a solution to protect the forums and groups if I want these features on our sites.
any solutions out there?
I am daily getting very much spams on http://placementmantra.net/
no idea how.even tried plugin no use
