You don’t need to be talking to a terror suspect to have your communications data analyzed by the NSA. The agency is allowed to travel “three hops” from its targets – who could be people who talk to people who talk to people who talk to you. Facebook, where the typical user has 190 friends, shows how three degrees of separation gets you to a network bigger than the population of Colorado. How many people are three “hops” from you?
~ from Three Degrees of Separation: Breaking Down the NSA's 'Hops' Surveillance Method by the Guardian US Interactive Team ~
Utilizing this interactive tool with the average of 190 Facebook friends, we find that the second degree (or "hop") nets 31,046 people and the third degree results in 5,072,916 people. Repeat this process over and over again with different individuals and you'll end up with almost everybody who communicates via the internet!
I hope you are able to discern the great danger here. By being "connected" with over 5 million people, you stand a huge chance of being "connected" to someone up to no good. More than likely, it is someone you've never heard of. It is someone you couldn't pick out of a lineup if your life depended upon it. It is someone who is a complete stranger to you.
From the standpoint of the NSA, CIA or FBI, none of that matters. You are connected by a mere 3 degrees! Because you are so "closely" connected, you must be watched. If a person only 3 degrees from you is up to no good, then obviously so are you!
In the end, almost everybody will be 3 degrees away from some sort of troublemaker which means ALL OF US will be placed under suspicion. That's WHY they have to watch everybody.