This document discusses the risks to privacy from scanners that can extract data from barcodes and QR codes on items like boarding passes, membership cards, and name tags. It finds that boarding pass barcodes typically contain traveler name, flight details, and loyalty program status. Other items can contain more private data like addresses and phone numbers if provided during registration. The document demonstrates how scanners can retrieve this data and how it could be misused to track people down online and discover additional private details. It recommends not opening unknown links from barcodes to avoid malware risks.