Hi!
Unfortunately, each of the components you mentioned (and many more you didn't) use arbitrary ways to handle user creation. However, the only create front-end users so they remain outside the scope of ATP. I have tried (and partly succeeded) adding a CAPTCHA to K2, but it required core modifications. Since modifying core files is a big no-no (not to mention it's strictly forbidden by JED rules) I consider this a non-solution, therefore I am not going to implement anything like that in ATP.
Nicholas K. Dionysopoulos
Lead Developer and Director
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