I had an interesting talk yesterday with one of our third year BSc students, whose dissertation I'm supervising. He has carried out two focus groups with his peers about how and why they share information on Facebook and Twitter (no further detail yet, as he hasn't finished writing it up, but I will add some more in the future).
Coincidentally, I came across this spoof documentary from Bubblegum Comedy about a Facebook privacy action group that I found amusing. I think the video dates from about 2010, so certainly not new. Humour is a subjective thing, and I don't think I'd actually show it all to students in class, in case some of this thought it was dull or lame & therefore got turned off the topic. However I could perhaps use a scene to get a discussion going on a specific point, or refer to it as an example of people's underlying concerns.