Yes, but for /whatever/ reason, they programmed their signup form to disallow signups from certain tld's, so a "me@somewhere.uk" (example pulled from hat) triggers their "don't allow from *.uk" error path.
They are not looking at where you "are", just what your email ends with. And why they are bothering to do so I don't know, as they seem to be overlooking the fact that the IRS insists that citizens pay income taxes no matter where in the world they are, and where in the world the income is earned. So a US citizen, living in the UK on a work visa, and earning income in the UK, and with a UK email address, is still required to pay the IRS their due.
They are not looking at where you "are", just what your email ends with. And why they are bothering to do so I don't know, as they seem to be overlooking the fact that the IRS insists that citizens pay income taxes no matter where in the world they are, and where in the world the income is earned. So a US citizen, living in the UK on a work visa, and earning income in the UK, and with a UK email address, is still required to pay the IRS their due.