""" They were quite mischievous jumping all over my equipment, and it looked like they were already posing for the camera when one hit the button,” he told The Telegraph in 2011. “The sound got his attention and he kept pressing it. He must have taken hundreds of pictures by the time I got my camera back, but not very many were in focus. He obviously hadn’t worked that out yet." """

http://www.telegraph.co.uk/news/newstopics/howaboutthat/8615...

There is some doubt whether Slater actually used a remote trigger, but that wouldn't have been as good a story as the "monkey selfie", so the image may not have gone viral, though he'd have a better case to own the copyright.