Actually, they've come up with a sustainable system where, in order to hire more border guards, they just need to be more aggressive in collecting taxes and duties for a bottle of shampoo, etc.

Then , in turn, the new border guards can aggressively ding Canadians for taxes and duties to pay the salaries for a new batch of guards.

And so on and so on.

Taking guards away to actually look for illegal migrants would upset the self sustaining system.