The link below has a story that is believable. (It is documented.)
http://www.businessinsider.com/apple-amazon-and-microsoft-are-helping-google-fight-an-order-to-hand-over-foreign-emails-2017-3At first glance it would seem that it is only about overseas e-mail.
But read on.
An amicus brief is filed by people or companies who have an interest in the case, but aren't directly involved. In this case, it's in Silicon Valley's interest to keep US law enforcement from accessing customer data stored outside the US.
An amicus curiae (literally, friend of the court; plural, amici curiae) is someone who is not a party to a case and is not solicited by a party, but who assists a court by offering information that bears on the case. ... The phrase amicus curiae is legal Latin.
