Jacob was traveling to Austria with an unlocked iPhone X on T-Mobile, but the SIM card he bought there for it didn't work. Phones can be locked to a carrier, but Jacob is saying it's not carrier locked. At least it wasn't when he bought it. It turned out that T-Mobile locked it after the fact. Leo says the FCC used to enforce this, and the phone companies would have to unlock phones after a reasonable time period. This all started when the phones were subsidized by the companies. Since Jacob paid for the phone in full, the companies shouldn't be locking it. There's no justification for it. It should be illegal, but unless the FCC enforces it, nothing will happen.
Leo says Jacob should tweet at John Legere, the CEO of T-Mobile: @johnlegere.