To the point about tracking... it's very possible to use Bitcoin completely anonymously. It's done every day in fact by users of a site called Silk Road which openly sells any drug imaginable and trades exclusively in Bitcoin, which makes it all possible. See here for a news clip about it:
As for being able to control it, no one can due to the way it works. It's decentralized - it works by all the people that make it up. Instead of explaining it technologically think of it like the people in a stadium doing the "wave". The wave is a single thing, but it only exists if all the people do it a certain way. Imagine a government trying to force all people in a country to do a "wave" which the government owned. This would never happen unless all the people agreed to do exactly what the government said. Bitcoin works in a similar way. I hope that makes sense.
Another way to think of it is like gold. Imagine a government claiming it will control all the world's gold. That can't happen. Gold exists in nature and is available to all that seek it out.
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