It was a thread on /gif/, btw.
>>15647072
/gif/'s archive is at desuarchive.
>>15647080
Here was the thread's url: >>>/gif/7276325
It has been deleted though and it doesn't come up on desuarchive
>>15647098
boards.4chan.org/gif/thread/7276325/girls-being-subtlediscretehidden
>>15647098
In that case, I'm guessing that some of the girls involved were underage.
>>15647119
Well shit.
I was looking for the webm of the chick in a yellow bikini masturbing in front of everyone on the beach.
I found the video:
http://www.ebaumsworld.com/videos/girl-touches-herself-at-the-beach/85000648/