> They're a private company

They are structured as a for-profit corporation, but they are a creation of a specific federal law, funded by the federal government as its sole active investor, and created as a federalization of the failing passenger rail industry.

They are very much an organ of the government.

Incidentally, the Supreme Court recently confirmed this in Department of Transportation v. Association of American Railroads, by a vote of 9-0.

It might be different between the Northeast Corridor and other Amtrak routes; I remember when they introduced the ID requirement a few years ago it was somehow rolled out more thoroughly on the Northeast Corridor. (I think I may have been asked for ID on the Lake Shore Limited and not on the Capitol Corridor.)

I don't recollect being asked for my ID while riding Amtrak on the Northeast Corridor in the last 2 years. I don't even print the stubs anymore - I just use the Amtrak app / Passbook on my phone to display my ticket.

Same here -- I take the NEC every month or so and have never been asked for my ID in around 3 years.

I was once asked for my AAA card when using that discount on the regional, but even that is extremely rare.

It's not asked on the train, it's asked when you buy the ticket at the window. If you use your CC, they then have id info presumably.

There are geographical differences.

Once in the South, I was fine just with an online receipt. Another time, going from LA to SF, I had to buy another ticket because my name was misspelled(seriously).

As recently as 2012, I was riding no the Northeast Corridor, usually out of Philadelphia, without showing ID. I just get the tickets from the kiosks, as far as I can remember they just needed a credit card.

I think maybe the tickets said something about "you may need to show ID to the ticket guy on the train", but I never had that happen.

A credit card is id, for all intents and purposes.