NSL is usually used specifically to indicated a National Security Letter issued by a US government agency. National Security Letters only apply to particular ty

NSL is usually used specifically to indicated a National Security Letter issued by a US government agency. National Security Letters only apply to particular types of information and even then only to transactional records and not content. They also must be targeted to information specific a particular investigative target. I would hope any company receiving a NSL trying to compel providing keys especially in some sort of automated way would challenge such a NSL in court.