Rebranding RFID: Don't worry, civil libertarians. The US government won't be using RFID tags (that's radio frequency identification tags or tiny computer chips that can be used to track one's whereabouts) to keep track of you. However, it's likely they'll instead use "proximity chips," "contactless chips" or "contactless integrated circuits." The re-branded chips, which may go in national ID cards or passports, have raised the hackles of privacy experts who fear the government will use them to track your next trip to Cuba or a visit to the local anarchist bookstore. Since the chips will also contain all the same info as a passport (name, date, place of birth, etc.), there's an even scarier possibility, according to RFIDkills.com:

In a dangerous world where Americans are targeted by thieves, kidnappers and terrorists, the RFID-chipped US passport will turn tourists into targets, and American business travelers will transmit their identities to kidnappers wherever they go, thanks to the US State Department.

Close up, the information broadcast from the RFID chip can be read by anyone with an inexpensive electronic reader.  Farther away, the RFID chip can be activated enough to identify the passport holder as an American.