Can watching photo's on facebook cause viruses?

[David]

I would not be willing to say it's impossible. According to leaked documents, the NSA was able to compromise certain computers that merely logged in to Facebook. But that actually had nothing to do with Facebook itself; the NSA computers monitoring Internet traffic just waited for the login attempt and then managed to send packets that SAID they were from Facebook but really contained malware - and since the computer was expecting packets from Facebook, they were accepted. But they could have done the same thing with pretty much any site.

That aside, it's possible if there's a bug in your browser. Normally an image is not supposed to run code, obviously. But if your browser doesn't process things correctly due to a programming bug, information that is supposed to be "data" can instead leak into the "code" area and run. This would be a rather serious security flaw, and I'd HOPE that sort of bug isn't currently out there in major browsers, but you never know.