” I had been curious about what’s in my travel dossier, so I made a Freedom of Information Act (FOIA) request for a copy.
“My biggest surprise was that the Internet Protocol (I.P.) address of the computer used to buy my tickets via a Web agency was noted. On the first document image posted here, I’ve circled in red the I.P. address of the computer used to buy my pair of airline tickets.
(An I.P. address is assigned to every computer on the Internet. Each time that computer sends an e-mail—or is used to make a purchase via a Web browser — it has to reveal its I.P. address, which tells its geographic location.)
The rest of my file contained details about my ticketed itineraries, the amount I paid for tickets, and the airports I passed through overseas. My credit card number was not listed, nor were any hotels I’ve visited. In two cases, the basic identifying information about my traveling companion (whose ticket was part of the same purchase as mine) was included in the file. Perhaps that information was included by mistake.
Some sections of my documents were blacked out by an official. Presumably, this information contains material that is classified because it would reveal the inner workings of law enforcement….”

More at Yahoo travel.