~60,000 google user accounts(not just email, but all your web browsing data) were handed over to the government in 2016. And this was under the Obama administration.
You can't write an executive order that says you can get access to something you previously needed a warrant for without a warrant.
Per "https://en.wikipedia.org/wiki/Foreign_Intelligence_Surveilla... : "and "agents of foreign powers" (which may include American citizens and permanent residents suspected of espionage or terrorism)."
Well, you can. If the US AG thinks it's illegal, you can fire her. If it's argued in court, you've got a floating SCOTUS appointment ready to make.
(The distinction between "can they do that?" and "can they legally do that?" is normally pedantic but at a time when CBP are reported to be ignoring court orders ( http://nypost.com/2017/01/29/customs-agents-ignore-judge-enf... ), this is becoming increasingly important)