Isn't that one of the first things they do when they identify + take down a site hosting CSAM?

pretty easy to copy and paste the question about 100 times to get the 1k char minimum :)

I imagine one of the ships officers will be tipped off by the IT team about the unusual number of free-internet activation attached to your booking id, and either give your room a visit to knock it off, or just bill some multiple of the $170 anyway.

It sounds like it should only be used only a few times per booking, and this is going to hit at least 4/hour for multiple hours a day, so it will stick out like a sore thumb in the logs ....

But, a cool hack, nonetheless :)

Ah, very good point.

Does it implement any of the dynamic features in PDF that are vectors for easy attacks like that?

PDF was originally a display-only format.