Flippanarchy

But why the fuck should it even be illegal to say that fbi breaks the law? First amendment anyone?

Also in the wiki (only relevant for the US, but that’s where Marlinspike is from and likely talking about):

That said, case law specific to the United States would render the covert continuance of warrant canaries subject to constitutionality challenges. West Virginia State Board of Education v. Barnette and Wooley v. Maynard held that the Free Speech Clause prohibits compelling someone to speak against one's wishes; this can easily be extended to prevent someone from being compelled to lie. New York Times Co. v. United States protects someone publishing government information, even if it is against the wishes of the government, except under grave and exceptional circumstances previously set by act and precedent. This may also have implications in regards to acting against a direct government intervention, similar to a government intervention against a warrant canary.

It’s not illegal (yet), so as long as you’re willing to fight an order to leave it up, you can ensure that your warrant canary is still effective. Either you take it down with no consequences, or you take it down, get arrested, and create case law.

Now, I wouldn’t trust most people or companies with a warrant canary to be willing to do that, but I’d probably trust a wc from Cory Doctorow, for example.

IDK if its true but I heard of cartographers doing something similar. Include some fictitious minor feature somewhere so you can demonstrate that someone has copied your map.

get the leak from two of them

Easier said than done to just magically have a second source leaking information to you.

As a very recent example:

Canadian election databases use “canary traps”—and they work

If I remember correctly, Marvel/Disney started doing this with the MCU (along with not telling some cast like tom Holland spoilers because they suck at keeping quiet), according to some of those "behind the scenes" type youtube channels (heavy spoilers, MasterTainment, Nerdstalgic, etc)

I've heard Peter Jackson did this with the hobbit and George Lucas with star wars, but I don't know how accurate those are, as I can't even recall where I heard them. So massive tub of salt and all that...

I've actually done this myself, when telling a story I've changed the names of some people involved, and when I inevitably heard back from someone who shouldn't have known, I know who told them based on what name are dropped. It helped cut someone shitty out of my life but I don't like essentially lying to and testing my friends...

Yes, all the canaries in today's discussion are metaphorical references to the literal birds, the "canary in a coal mine."

Coal miners were often killed by suffocation when they would accidentally release or encounter pockets of carbon monoxide, which was odorless and invisible. (Edit: also possibly other toxic gases) So they began carrying a canary in a cage with them. Being little, it was more susceptible than they. If the canary keeled over, you knew to get the hell out of there! Of course many canaries died. But the miners grew fond of their little yellow chirpers, and started to be more vigilant against the effects of the carbon monoxide. Like if the bird stopped singing. This was a win-win, because fewer miners died as well.

Edit to add: And they sometimes even attached a little O2 tank to the cage to save the canary. WWI tunnel mine exploding teams sometimes used canaries as well for the same thing.

Tyrion Lannister does this in Game of Thrones (I want to say in Clash of Kings, but it's been like 15 years since I've read the books)

Actually, the anime The Promised Neverland does it, too.

In the A Song of Ice and Fire books, followed by the unfortunate show made from them, Tyrion Lannister also does this with Little Finger, Varys, and Maester Pycelle. I'm pretty sure it's also used in the Deniro/Pacino movie The Heat. I don't think this exact story device really has a set name per se, but similar things have been called canary traps, so maybe that's part of why you were reminded of it in relation to warrant canaries. Broadly speaking, it's a mole hunt. A very similar concept but not exactly the same would be a steganographic leak test which is what @fizzle@quokk.au commented about.

No, it's a sign that warn that it has been raided after it's gone. It says nothing while still up.

In the most simplest terms, it’s a statement of a negative that, when removed, implies a positive.

You can use them for anything.