Not GP, but I would assume:

> As of the date of this report, Uber has not received a National Security Letter or FISA order.

Has the legality of removing that canary, if they were to receive an order that requires secrecy, been confirmed or tested in court ever? I.e. the claim of "we didn't tell people you served us an NSL, we just stopped telling people we hadn't, so we didn't break the instruction to not tell anyone"?

Well, by its nature it wouldn't be an open proceeding because of the pure ridiculousness of secrecy in these types of cases, so we might not be able to confirm it like that. That said, I haven't seen anyone arrested at any of the organizations that have removed their canaries yet, so it seems like the legal theory remains as sound as expected.

Warrant canaries are so vague that it may technically breach the gag but it doesn't give any information that the gag orders attached to/in NSLs mainly that the targets of NSLs can't find out that their information was requested. Once a year site/company wide canaries provide no actionable information and don't even threaten to expose abuses that would show up as an inordinate number of letters being sent to a particular company that I doubt the government really cares about them in the slightest.

Don't get your hopes up. Laws are interpreted and applied by humans. If the order says you can't tell others you got the letter, no amount of information-theoretic trickery gets around that.

This can require you to lie, and I hate such laws, but that only happens if you deliberately box yourself in by setting up a warrant canary. You can avoid lying by sticking to a policy of "we cannot comment on whether we have received a request with a gag order".