On another thread admin said

No way to disable registration. Set registration require approval.
If I set registration approval I STILL get 40 bogus members waiting approval, I then have to delete them one at a time.

There must be a way to stop these bogus registrations. If I go on vacation this week I'll come back to about 500 bogus members, deleting them will take about 1 hour.

Not good eh?

Please help.