Huge sudden increase in spammer/fake account registration?

[Janfri]

I don't know if it is the solution, but I checked "Random images" in the Image Verification Options and did not have any bot registration since yesterday, after having 10 the night before. Hopefully this will at least reduce spam. But I still wonder how new user moderation can be bypasssed. About 50% of the at least 40 spammers on my site in the last week bypassed the moderation.