It's not that hard to guard against their trackers. More critical, from my point of view, is the fact that, assuming you have a normal social life, snapshots o

It's not that hard to guard against their trackers. More critical, from my point of view, is the fact that, assuming you have a normal social life, snapshots of you show up on FB. And people identify you in those snapshots. So anybody with access to that data can build a partial timeline of what you do, who your friends are, and where you've been even if you've never created an account. It's big brother implemented through the people around you.