I heard about warrant canaries and thought the idea was interesting. My understanding of what they are is a website or online service publishes a statement periodically that they have not been served a warrant. This way even with a gag order, the act of not publishing something is not infringing it. I hear warrant canaries don't actually work as a judge would likely find not publishing something to signal a warrant has been served would be in violation of a gag order.
My question is, is there an alternative to a warrant canary that would serve the same purpose (but actually work), that an online set or web service etc. has been ordered to change their behaviour by the government/police/rebels etc.? I'd imagine something Tor or P2P related could be used to spread the message "hey, we were forced to hand over user information".
Correct me if any of the above information is wrong; I'm not well versed in law, but do find this idea interesting.