failblog, icanhas, roflrazzi, onceuponawin... how are they still open?

All of these sites, and the rest of them seem to be infringing on image's copyrights, over and over again. I'm wondering if they are under fair use or? How are they still doing this? I know they make hundreds of thousands if not over a million in ad rev per year?

 

Probably because the pictures from the originals are public domain or stolen aswell?

 

Parody makes it a different story I believe.