Don’t throw away items such as boarding passes, driver’s licenses, credit cards, or anything that has a bar code, QR code, data matrix, or postal code. They should be shredded. There are all kinds of shredders available, even those that will shred credit cards. They may hold more information than you realize. So what? Someone could use this website to decode the information and learn more about you.
This article tell about the information someone found from his boarding pass. It showed his name, frequent flyer number, other personal info, and his record locator. Using this, the account with the airline can be accessed. Future flights were seen as well. Seats can be changed, a PIN number reset. If someone really wanted to get into it they can figure out more of your information. They would have your address and know of a future flight so your home could be robbed.