The irony of this question and the responses that most surely follow (Not me...not happening...) is the scariest thing since the first "Nightmare on Elm Street".
There is much to be gained by having such a device placed within you as long as it is undetectable. If used properly, this device could relay medical complications before they actually develop symptoms, or just be used to identify you in place of a lost too often identification card. If this sort of system was imposed, then the problem with identity theft could be erased, and ultimately end up saving the average consumer immensive amounts of money by the fact that identity theft bullets would not have to be bitten on by businesses.
I understand where the true resistors to this sort of revolution are coming from. The idea of "Big Brother" having you tagged with a microchip is a scary concept. I figure that the same way that it could trasmit small electrical signals to be deciphered by other environmental receptors for your benefit, it could be used in reverse so that you can be controlled via small electrical pulses at the brain's frequencies...
I assure you, however, my friends that you should not be scared of the government having some master plan with monitoring you or controlling you... They already have been for a great amount of time.
How? Your wonderful social security number is your bar code and public media (music, t.v.) has been subliminally controlling you for decades! Is it no wonder that radical music ends up in one of two ways: commercialized and dumbed down or under-funded and hardly distributed...? Look at rap music from the nineties and from the present...How about rock...?
Hmmm...
That's food for thought...
Hope that helps...