My friend told me he posted about this thief using other people's photographs to create vectors:

http://submit.shutterstock.com/forum/viewtopic.php?t=93175 [nofollow]

See this thread too http://www.microstockgroup.com/image-sleuth/yet-another-infringement!/msg167324/?topicseen#new
If your friend has spotted more cases of the same thing he or you need to post them on MSG or the SS forum.
It seems to me they never even bother to look into things if you just email admin (or maybe it just ends up at the end of a very long q?) Either way it seems half the people that complain about infringements say they are posting on the forum out of desperation because mails to admin get zilch in the way of action.

ETA I love the response from the other contributor on SS, doesn't care "this stuff happens all the time".
Well yeah, it does on Shutterstock because they don't ask for a source file or any kind of proof that you have copyright to your sources. They're just interested in pushing through as much crap as possible into the collection as they can.