Does Facebook's new privacy tool clear your data?

The keyword is: clear. Facebook's new tool will decouple all the information they have about you from your account but it won't actually delete it from Facebook servers.

How come Google stopped sharing data about network coverage?

Google had this cool program where they used Android information to tell cell carriers in rural areas where people weren't getting service. They stopped it though because of all the concerns about privacy.

What is a YubiKey and are they safe?

This is a YubiKey It is a little tool for creating what's called two-factor authentication. When I log into my Gmail I enter my password and this key into the computer. It means that for somebody to hack me they need to steal both password and the key. It is a good thing to have and seriously everybody should be concerned about safety online and use two-factor authentication in some way or another.