b) there doesn't appear to be any guarantee that failing to update the canary would not be considered breaching any "do not reveal" clauses of any court orders that had already been received. At most serious it would likely be down to a judge's opinion. e.g. a judge *may* decide, "the court order clearly says that the fact you've been served a court order must not be revealed. You chose to stop updating your canary with the express purpose of alerting the subject that an order may affect them, therefore you're going to be prosecuted."
AA patrols on bicycles warned motorists of police speed traps ahead. In 1910 in legal test case ('Betts -v- Stevens') involving an AA patrolman and a potentially speeding motorist, the Chief Justice, Lord Alverston, ruled that where a patrolman signals to a speeding driver to slow down and thereby avoid a speed-trap, then that person would have committed the offence of 'obstructing an officer in the course of his duty' under the Prevention of Crimes Amendment Act 1885.[4][5] Subsequently the organisation developed a coded warning system, which was used until the 1960s, whereby a patrolman would always salute the driver of a passing car which showed a visible AA Badge unless there was a speed trap nearby, on the understanding that their officers could not be prosecuted for failing to salute.[6] The AA Handbook included the following message many times "It cannot be too strongly emphasized that when a patrol fails to salute, the member should stop and ask the reason why, as it is certain that the patrol has something of importance to communicate.[2]
The Automobile Association was founded in 1905 to beat 'unfair' police speed-traps - for which its famous salute was a secret weapon, and originally owned by its members.
The famous salute harks back to the pioneering days of early motoring when speed limits were less than ten miles an hour. AA officers on bicycles would point out hidden police speed traps to motorists.
This led to prosecutions for obstructing the police, so the AA salute was developed. If an officer did not salute a member it was a signal that a trap was nearby. Police were scarcely able to prosecute AA men for not saluting. The AA discontinued the salute in the 1960s.