The TSA knows a lot more about passengers than they probably should. According to a New York Times article, the Transportation Security Administration has access to several huge federal and private databases that it uses to keep track of people traveling via U.S. airports.

Among some of the information found in the databases is tax identification numbers, old travel plans, property records and even physical characteristics of passengers. The information is shared among government agencies.

The article says that data-mining is being used by Department of Homeland Security agencies like the TSA to keep track of suspected terrorists and criminals. The TSA uses it to take time off of lengthy pat-downs at the nation's airports. The TSA argued for this technique as a way to ensure that airports are truly safe but some privacy advocates are not happy with the technique.

The Times says that the TSA doesn't just conduct routine background and criminal checks on airline ticket holders anymore. They also use these databases to look out for red flags.

"I think the best way to look at it is as a pre-crime assessment every time you fly," Identity Project consultant Edward Hasbrouck told the Times. "The default will be the highest, most intrusive level of search, and anything less will be conditioned on providing some additional information in some fashion."

Hasbrouck had sued the federal government before to try to learn about the type of information that the TSA compiles on travelers. He always believed that more information was being collected.

The TSA's effort to gather information is continuing to grow, the Times reports. "For instance, an update about the TSA's Transportation Security Enforcement Record System, which contains information about travelers accused of 'violations or potential violations' of security regulations, warns that the records may be shared with 'a debt collection agency for the purpose of debt collection.," the article says.

 "A recent privacy notice about PreCheck notes that fingerprints submitted by people who apply for the program will be used by the FBI to check its unsolved crimes database," the article added. PreCheck rolled out at airports around the country earlier this month.

The TSA will be able to get information to profile travelers based on their past travel itineraries, property records, car registrations and employment information. This calls for a full background check which will lead some passengers towards lighter screenings and others towards a more invasive bag check and pat-down. The TSA says it has a goal for qualifying at least one in four passengers for lighter screenings, meaning the traveler wouldn't have to remove their shoes and the screening would be faster.