don't share shit you don't want people to see. no matter your privacy settings, if you're like most people and use the same password for everything, shit can still get out.
stuff like my twitter and my facebook are all things i don't mind people knowing. sometimes it can make me look a bit silly, but i wouldn't put it out there if i wasn't happy with it out there.
and the video can make a good point, but the fact is you click on a big button that says "i'm happy for this to trawl through my stuff" to achieve the lack of privacy effect.