The officer was not reading the emails of a US citizen, he was reading the emails of a Thai citizen attempting to enter the US under suspicious circumstances. The fact a US citizen may have sent emails to her or received emails from her is not a violation of their rights. If you don't want anyone to ever read your communications, do not send them. The government can and does read your posts, emails, and listen to your phone calls.

I really find it suspect and doubt this story as written.