I get about 20 spammer registrations on my site daily. I've got captcha installed and it helps a bit (I used to get hundreds daily.) But I need more and K2 is a bottleneck/problem in this regard. If I want to use K2 registration I have limited options. Some things I'd like to see in K2 that would help:

* Allow me to use any other captcha system - I understand that nocaptcha will be supported soon, but this is not enough. I need many more choices.
* Allow me to create a custom question - Real users registering on my site will know the answer to a question that I can ask.
* Integrate other spam blocking systems - There are systems out there that check against black lists and white lists... I can't use them with K2

Is anybody else getting this problem with spam registrations? Have you found any solutions?

Oh, yes, before you ask, I have eliminated all reasons for a spammer to register... they can't comment or create articles or send email. They are just dumb bots registering for no good reason.

Is it just me? I've had 5 more spam registrations since this post... in just two hours.

You can also add Stopforumspam.com
If there are getting past stopforumspam and reCaptcha, then it is possible that real people are creating these accounts.

Nope. I don't believe they are real people. According to Google Analytics I have about 10 unique visitors per day. Somehow this translates into 20 or more user registrations per day.

I need more options to eliminate spam.

Did you enable stopforumspam?
You can deactivate K2's recaptcha, switch to Akismet and try other security extensions.
If this does not stop then they are indeed humans behind this.
I have see this before, they even signed up through FB (a bot does not have a phone).