How can Facebook both allow a user in the EU to send messages to a group of people in the US and not store data in the US?
There's a word for businesses that are systemically unable to comply with the law.
I don't know if Facebook is one of those, but it might be. Shutting down is always an option for that kind of company. Nothing of vale would be lost.
Facebook has not claimed it's not technically possible.
Yeah, it does. A person in the US is not a server in the US. It's an iPhone in the US, not a server.
Does it really take that much of a leap of logic to understand that the server doesn't have to be on the same continent as the user?