If someone is inside of my house, and they are legally allowed to be there (i.e. I've invited them in), then I have zero problem with them using my outlets to charge their phone.
If someone is on the train, and they are legally allowed to be there (i.e. they have a valid ticket), then I have zero problem with them using the train's outlets to charge their phone.
If someone is in a government building, and they are legally allowed to be there, then I have zero problem with them using the building's outlets to charge their phone.
Little known fact about Middle Earth: The Hobbits had a very sophisticated computer network! It was a Tolkien Ring...