One option would be that if an officer would like to search a cellphone, he would need to fill out a piece of paper and ask a supervisor to sign off. There would be a report written, not only about the decision to search an electronic device but what they are looking for on that device.
Let's just say that they are looking for the invoice concerning a particular camera that they think was purchased outside Canada. You could narrow what they are looking for. They can't go on a fishing expedition if, in that form, they need to state specifically what it is they would like to search. If what they want to search is, say, a lawyer's laptop, we would be able to stop them from looking for information about a particular client.