http://cacm.acm.org/magazines/2009/12/52836-a-threat-analysis-of-rfid-passports/fulltext
The Final Analysis
Having looked at the potential attack, the costs of that attack, and the returns, we can now ask how concerned we should be about such an exploit. Should you really be worried as you walk through the airport that someone behind you might be stripping you of your passport information in a grand scheme to rob you?The technical hurdles are surmountable, at least in proof-of-concept demonstrations. It is possible that such an attack could occur, but this possibility must be balanced against the complexity of the attack, the difficulty of obtaining the required high-priced blank passport, and the limited return the attack is likely to produce.It seems much more likely that most perpetrators would resort to old-fashioned means of stealing your passport information, by stealing your physical passport itself. We recommend that it is more important to be careful about keeping your physical passport safely in hand than to be wary of perpetrators lurking behind you in line at the airport attempting to exploit the RFID tag in your passport.