Weird Captchas'?

Have you seen weird captcha's? Like what?

Forumotion's captchas are weird,and they dont provide much safety.
The best captcha is re-captcha

I was totally going to make a thread on this but never did.

I even have a picture and I meant to take more of weird ones I received:



I've seen very tiny vertical lettering, letters that aren't on the standard US Keyboard, and things that you just can't read. The thing is though that I've got passed a lot of them without typing in the right thing, so what are they really attempting to do?