Comment by lysace

That concept has always sounded like tech people trying to hack the law without the proper real-world legal knowledge, IMO.

Bruce Schneier wrote in a blog post that "[p]ersonally, I have never believed [warrant canaries] would work. It relies on the fact that a prohibition against speaking doesn't prevent someone from not speaking. But courts generally aren't impressed by this sort of thing, and I can easily imagine a secret warrant that includes a prohibition against triggering the warrant canary.

Lots of similar discussion on HN already, e.g. in https://news.ycombinator.com/item?id=5871541.