Disagree with people who think these losers have the "right" to walk off the job...it's an escential service as far as I'm concerned... just like police, fire, ambulance, doctors, air traffic etc etc... they knew full well what they were getting into when they took the job... they have NO RIGHT to walk off and they should all be fired, guns or no guns their union is screwed in the head.
First of all, EVERYONE in Canada has the right to refuse work that they feel is unsafe. Second, law enforcement personnel are trained to deal with dangerous people, and are armed. The Customs personnel are not trained as law enforcement, and should not be expected to act as such when dealing with dangerous and armed individual(s). Firemen are trained to deal with their job-specific dangers, and if faced with others, call the police. Doctors have refused to work recently, but not because of a patient in their place of work that might shoot them. And I don't think that air traffic controllers are often faced with a dangerous person entering their workplace.
So, your arguments about other professions not having the right to walk off is not relevant, as they are not dealing with the same situation. IMO, the Customs agents are not an "essential service", as in no one is going to get hurt/injured if they do not do their job. See quote below, taken from http://www.lrb.bc.ca/mediation/
"Under Section 72 of the Labour Relations Code, the Labour Relations Board has the responsibility for designating the “essential services” that it considers necessary or essential to prevent immediate and serious danger to the health, safety, or welfare of British Columbians during a labour dispute."