The example in this video is kind of like a practical joke, or a really ill-conceived science project. If you have teenage sons and live near a beach, you might want to hide this video from them.
You could probably track down at least some of the pranksters through the YouTube account that posted the original video. But the people who were hit with poop would have to prove they were damaged by the poop, and that the birds that pooped on them were the same ones that ate the laxative-laced Pringles, and that there is a monetary amount to their damages. It would not be an easy task.
This video has been out there for about 7 months, and has been viewed over 3,000,000 times. I have to wonder if PETA members have gotten their dander up over these kids and their practical joke. If so, they should just re-laxative!