[tobster1911]

I work with RFID for a living. Here are some things that should clear up a few of the questions.

RFID works on specific frequencies.

The most common is 125kHz. This is the frequency used for access control doors, animal ID, automobile immobilizer, ect. This has a range of only 1-12 inches.

The next most common frequency is 13.56MHz. This is used mainly for secure applications. These are passports, credit cards, ect. These have a range of about 24 inches best case.

Both of these work on magnetic field not electric fields.

The most resent is UHF. This is the "Walmart" driven RFID tags. They use 868MHz (EU) and 915MHz (US). These have a range of around 30ft. They are very large in size (credit card size).

There are no fully passive RFID tags that can be read from satellite that I am aware of.

The easiest to implant in a human would be the 125kHz. They already use this in cows, pets, ect. Range is very limited due to the size of antenna. Only 1-2 inches in this case.

RFID scare aside, this is very fun technology.