Just harassment of a guy crossing the border. Any truly malicious person could just wipe and restore the phone/computer before and after the crossing either from the internet or locally so it is a waste of everyone's time and invasion of privacy.
As an aside I am not surprised this happened in Canada. I lived in Canada for a few years and then returned to the UK. It's not obvious to people who have not lived in both places, if you only visit you would not see this but Canada carefully cultivates an image of itself abroad and there is a stark difference in how authoritarian Canada is compared to the UK. I still know people who live there and the way the authorities at all levels treat even their own Canadian citizens would not be tolerated in the UK. Often times you cannot talk about this with Canadians as they will defend the way things are done and say the infringements on freedom are for a good reason. The citizenry is generally happily compliant and only outsiders who are used to more freedom notice it.
I think the compliance reasons are why they also put up with government restrictions on business in telecoms, air industry and even the dairy industry, look up the Canadian cheese smuggling arrests made a couple of years ago :-)
Canadians also rejected the UK style totalitarian blanket surveillance and internet filters so not sure what 'freedoms' they are missing out on compared to the UK. All those same kinds of gov interference and regulations in airspace and dairy exist in the UK too, and every other country.
Border guards demanding your phone will likely happen in every country soon if not already. They take mine at US border and France.
Telecoms in Canada are just as corrupt as the US where they established monopolies long ago and now squat on spectrums to prevent any new competition. Huawei almost bought their way in to Canada then the Americans panicked and the deal was lost http://www.cbc.ca/m/news/politics/canada-at-risk-from-chines...
Of course regulations exist in every country but it's the extent to which they limit competition resulting in poor service and high prices that affects Canada particularly badly. For example, tv/internet services Rogers/Bell provide are abysmal compared to the likes of Sky and they charge many times more too. Same with cellular plans. Really though we're getting side tracked, I do not think border guards demanding your phone will become commonplace in every country like you say because of both privacy concerns and because of the fact that people with malicious intent are not going to be caught out. This is not like a car where drugs may be hidden inside the trunk, you can completely wipe the phone and just get data back as soon as you exit the airport.
Some countries (China/Israel) they disappear with the phone likely to load it full of nation state spyware I would never trust that device again even after flashing a new application OS.
As an aside I am not surprised this happened in Canada. I lived in Canada for a few years and then returned to the UK. It's not obvious to people who have not lived in both places, if you only visit you would not see this but Canada carefully cultivates an image of itself abroad and there is a stark difference in how authoritarian Canada is compared to the UK. I still know people who live there and the way the authorities at all levels treat even their own Canadian citizens would not be tolerated in the UK. Often times you cannot talk about this with Canadians as they will defend the way things are done and say the infringements on freedom are for a good reason. The citizenry is generally happily compliant and only outsiders who are used to more freedom notice it.
I think the compliance reasons are why they also put up with government restrictions on business in telecoms, air industry and even the dairy industry, look up the Canadian cheese smuggling arrests made a couple of years ago :-)