I think the title asks everything so: Where can you buy pictures you're allowed to use in Facebook "testimonials"?
I know a lot of people just rips these but I'm not sure if I should because you can get in a looot of trouble.
Is there any place people sells their pictures with licence to use them in any advertising?
Fiverr, stock photo sites
Try these:
http://www.designskilz.com/random-users/
http://uifaces.com/
Amy