I think Facebook is totally manageable. Max out the privacy settings, that way you can approve everything and anything you are tagged in. As far as the cookie goes, I use Google Chrome which has an awesome extension called Facebook Disconnect, it blocks Facebook from tracking webpages you go to. I like the idea of a VM, I use one for work all the time. For those of you interested, VirtualBox is free. Bottom line, none of the social networks out there are really "safe", just be careful about you put out on the net.