They are small enough and cheap enough to put just about anywhere, which I don't like. A way of keeping tabs on us all.
Big brother is going to be very bored then.
Why worry about governments, etc, keeping tabs on you? It is only a problem if you are doing something illegal.
Unless you don't use the internet, cell phone, gps or credit card, there are plenty of traces for big brother to watch already
No need to worry, but it's a good reason to think about who you vote for.