I think deleting something would be considered an active action. The trick with a canary is that you're choosing not to do something, so it can't compel you to act (as compared to, for example, telling you you can't delete the canary).

So for it to work, you need to issue a statement every month that says you haven't been issued a NSL, and then simply not issue a statement the month you finally were issued a NSL. That would then require the government to actually compel speech (compel you to post a new notice saying you didn't receive a canary).

Of course, the above should make it blatantly obvious how absolutely absurd the blanket gag order on NSLs are.

It's not necessarily deleting anything. Reddit states in its transparency reports that it has not received any NSLs. The idea is that if they ever received one they would simply omit that clause from the next report (not remove it from prior ones).

Interestingly, if you accept that code can be copyrighted, and that only things that are expressions (speech) are eligible for copyright ("A copyrighted work must be an original work of authorship which is fixed in a tangible medium of expression"), then code == speech.

So, by compelling Apple to code something that doesn't exist, the government would indeed actually be compelling speech.

Court processes involve compelled speech all the time. Heck, compelling witness testimony, which is one of the most well-established parts of the court process, is nothing but compelling speech.

So, I'm not sure what the value is of a clever argument that compelling Apple to comply with the order here is "compelling speech" is supposed to be (likewise, the upthread one about NSL canaries.)

Fair points that I concede. I'll note I also forgot the nuance mentioned by morsch (that a canary is compelling a lie, which is potentially different).

On a separate note though, I've always thought it would be interesting to see a member of Congress be issued a NSL and then have them read it on the floor of the House/Senate (since they have parliamentary immunity for anything they say on the floor of the House or Senate).

Compelling speech is a thing that happens under certain circumstances. E.g. subpoenas, witnesses in court. Though those are clearly different from a canary, not least because producing such a canary would not just be compelling speech, but compelling a lie.

That's not how canaries work. You don't delete them, you fail to update them.