As of now, my understanding is that we're talking about Canadian citizens who are returning to Canada that have been to Syria, Iraq and such, some of which might have been in Isis. Realistically, what could you do about those if you have no proof whatsoever whether they were in Isis or not? Many of those people are just coming back from the middle east and are completely legit. The situation is different if there is evidence that someone was in Isis, obviously. Those people are getting tried.
I don't think the actions of Canada are all that much different compared to those of any other countries. And I can't imagine it being any other way. I have friends here in Canada who are from Syria, one of my best buddies over here is, and he is also an executive at EY, which has its presence in Syria too, so he sometimes travels back and forth. Some of those guys are great people, they have been in and out of Syria, so making life difficult for thousands of them would be a horrible thing to do.
Honestly, a bigger problem Canada, and especially Ontario seem to have is gun smuggling from the US, and refugees coming in from the US illegally. Those are the bigger issues that the border services seem to have at the moment.