The monkey took the image with a camera set up by British nature photographer David Slater.
PETA ( The Animal rights organisation People for the Ethical Treatment of Animals) has filed a complaint on behalf of the monkey, claiming that it should be declared the owner of its own image.
http://edition.cnn.com/2015/09/23/world/monkey-selfie-peta-lawsuit/
http://www.cnet.com/uk/news/peta-sues-on-behalf-of-monkey-who-took-selfie/