Bob is a hacker. Just over three months ago, they found serious vulnerabilities in Frontier Airlines' API and website that would let anyone with a boarding pass code for a flight retrieve every passenger's personal information, including but not limited to home address, nearly all credit card info, full passport details, and even TSA PreCheck codes. The boarding pass code (called PNR) is written on the pass itself, or scannable via its barcode; plus, since it's only six digits, it's easy to loop through, something they replicated to find several passengers' full info.
Bob notified Frontier about the problem, but the company did very little to fix it; getting a hold of the aforementioned info now required the passenger's last name, also printed on the pass. So they published a post on their blog detailing several vulnerabilities in Frontier's website.
