Wow, these are pretty bad. The "Sliding CAPTCHA" is simple but tedious to slide the slider to the exact right number. The "Image rotation CAPTCHA" can be very

Wow, these are pretty bad. The "Sliding CAPTCHA" is simple but tedious to slide the slider to the exact right number. The "Image rotation CAPTCHA" can be very difficult for some images. (for example I got a wind turbine where the shaft wasn't perfectly vertical in the image, so I had to guess if it should be slightly left or right leaning. I did get it right but I had low confidence) The "Alphanumeric CAPTCHA" was ok but some of the numbers were fairly obscured. For the one I got (the line ran right though the string, this seems rare, usually it only interacts a few characters). But not only are these awful for humans it seems like they would be pretty easy to solve for robots. The image one maybe a bit hard, but that was also the least confident for myself.