We have that on our website with the image containing a key to sign up, but we still get anywhere from 2-6 these bogus signups daily.

Ours have emails that end in names like:

@cashette.com, @bestboyfilms.com, @ukr.net, @telegraf.by, @mail.ru, @web.de, @statistics-fund.com, @inmail24.com,@gawab.com ...

there are others, but those are only the ones that have tried to sign up in the past few days.

On our site we do have it so they have to be approved, and we now know that we have to ban anyone with a birthday of March 28, 1983 and one of those strange email addresses.

They still try daily, but at least they never get to the point where they might post or send members emails.

Unfortunately they must also have IP masking (which shows us a bogus IP) because each one of these that try has a different IP address, so it becomes almost impossible to track and contact the service provider.