How are spammers still getting through?

[محروم.كوم]

So, not only do I have e-mail verification on, as well as the image verification, but I added some required questions to stop spam scripts getting in where they need to type in an extra answer to a simple question to get through registration.

And yet I still get a spam account or two set up every week or so.

Are these actually people going through the trouble of creating accounts? Or are their scripts just getting that much smarter to get through all of the spam protection?

I don't have any issues banning them when they pop up, but its more just curiosity at this point. __DEFINE_LIKE_SHARE__