viewing pictures

I have noticed that a lot of pictures just have a blue box with ? mark in side what is this something new I can't seam to see any of them, when I click on box it takes me to a web sight but still can't see picture.
due I need to down load a special app to view, or get clearance ?

Been removed from people's photo sharing most likely

Or you firewall / ISP / Employer blocks file sharing sites

ok thanks i have a Mac Book Pro, at home that al I use but I am not very Computer savvy