So Yahoo! helped the gummint trawl through Yahoo! emails. And, presumably, not just the emails of Yahoo! users but all the emails you sent to friends with Yahoo! accounts and all the addresses (like firstname.lastname@example.org) that forward to Yahoo! accounts.
Of course, those of us who care about privacy are all bent out of shape.
But don’t forget that the original FISA (Foreign Intelligence Surveillance Act) was introduced in the Senate by Ted Kennedy, passed by a Democratic congress, and signed into law by Democrat Jimmy Carter.