When you've returned home from a flight, you might be tempted to toss out your boarding pass. However, that document has a ton of personal information about you, and some of it isn't obvious. Shred it instead.
As information security blog Krebs on Security points out, your boarding pass is a treasure trove of information. In plain text, you'll usually have your first and last name, flight number, and more printed right on the pass. Even if you're not worried about that, however, those bar codes hold even more information:
"Besides his name, frequent flyer number and other [personally identifiable information], I was able to get his record locator (a.k.a. "record key" for the Lufthansa flight he was taking that day," Cory said. "I then proceeded to Lufthansa's website and using his last name (which was encoded in the barcode) and the record locator was able to get access to his entire account. Not only could I see this one flight, but I could see ANY future flights that were booked to his frequent flyer number."
Of course, every airline has a different method for storing information on their boarding passes. Even without encoded information, the data that's plainly visible on your boarding pass should make it worth shredding. If you were thinking that you're not worried about the information you can see, though, it might be worth taking precautions anyway for the information you can't see.