The State Department is rolling out new passports that make use of RFID Tags.
This would put all Americans traveling abroad in extreme danger, as their passports would be homing beacons for thieves, rapists, kidnappers, and terrorists.
Note: NPR did a great story on this, no transcript but listen here.
RFID tags are memory chips that can be read wirelessly. These chips are cheap to make, can carry a lot of information, and don't need an internal power-source (i.e. batteries). They can be read as you enter a room or step onto a plane, without your consent or knowledge.
From Wikipedia,
Passive RFID tags do not have their own power supply: the minute electrical current induced in the antenna by the incoming radio-frequency scan provides enough power for the tag to send a response.
In 1999 I worked for a company developing RFID technology. At the time, these tags could be detected from fifty feet away, but I wouldn't be surprised if they could now be detected from hundreds of feet away or more once there was this kind of interest.
This is especially dangerous in passports because the chip can't be turned off -- it is broadcasting its signal whether you like it or not.
While traveling it is smart to keep your passport on you at all times, but with today's world-wide political climate, it is a very dangerous time to have a big red flag labeling you as an American anywhere you go.
Thugs could just scan a walk-way for Americans and use their detector to decide whom to mug, rape, kidnap, or murder. Once they have you, they will know exactly where your passports (and any valuables kept with it) are hidden. If your car or hotel gets broken into, thieves could find your passport right away without any trouble by simply running a scan. This would be much easier than even using a metal detector as the signal would be giving out the passports exact location.
I've had my things broken into while visiting many countries (France, Tunisia, Turkey, Israel -- and in the USA), passports are very popular among thieves as is the money they are often kept with.
Additionally, the information on these tags could easily be read by anyone with a scanner, without having to even come in contact with the actual passport to let you know your privacy was compromised. This opens a whole new world of security issues depending on how much information the government chooses to store on these chips.
Officials are saying that the information on these tags would be protected through encryption, but I don't think that's good enough. I would bet hard cash that once the passports start rolling out, it will be just a few weeks (if not days) before some tech students somewhere crack the code. Just look at how long it took for DVD encryption to get hacked!
Officials are also saying that the passport's "jacket" would include an aluminum-foil type material to block out the signals from your RFID tag so it couldn't be read unless the passport was open. While aluminum foil does a good job blocking RFID signals, this just isn't good enough. I don't know the specifics for what the government has in mind, but I don't imagine it being full proof especially once criminals are actively trying to find ways around it. And a passport has to be opened when used as ID (at a hotel, bar, or whatever), and can easily open a crack (or more) while in your pocket or backpack.
This is especially silly because there are plenty of ways to store extra information on a passport without the risks that RFID tags would introduce. If the government does not intend to read people's passports without their knowledge, why not use a technology that requires a passport to actually make physical contact with the scanning device (like a magnetic strip, three dimensional barcode, or flash-memory card)?
Moving forward with RFID technology in passports is just plain dangerous, especially since safer and cheaper technology exists that can do the job. This is being done in the name of national security to protect us from terrorists, but it does exactly the opposite.
Update: These will start being issued THIS YEAR. My advice: Re-new your passport NOW, because old passports will continue to work up until their expiration date. Thanks Deepintheheartoftx!