When is a rule not a rule? When it comes to government doubletalk. If you read below, cut and pasted from tsa.gov, it says an officially-issued
ID MUST be presented (notice you can get away without photo
ID for domestic flights), but then it says if you don't present it you MAY be denied boarding. If it was truly required, it should say you WILL be denied boarding. Sounds like they left it intentionally vague enough to be selectively enforced, sounds like a big loophole to me, and it ought to be filled.
Proper Identification
If you have a paper ticket for a domestic flight, passengers age 18 and over must present one form of photo identification issued by a local state or federal government agency (e.g.: passport/drivers license/military
ID), or two forms of non-photo identification, one of which must have been issued by a state or federal agency (e.g.: U.S. social security card). For an international flight, you will need to present a valid passport, visa, or any other required documentation. Passengers without proper
ID may be denied boarding.
For e-tickets, you will need to show your photo identification and e-ticket receipt to receive your boarding pass.
There are four ways to obtain a boarding pass:
Go to your airline's ticket counter at the airport
Use curbside check-in
Use your airline's self-service ticket kiosk in the airport lobby
Print the boarding pass from your airline's website
Note: Persons with parental, official, medical business or similar reasons may be able to access the checkpoint, but should check with their airline for required documentation.