I have been asking this question myself. To a technologically nerdy person like myself it makes absolutely no sense. There is no reason whatsoever to physically

I have been asking this question myself. To a technologically nerdy person like myself it makes absolutely no sense. There is no reason whatsoever to physically transfer any dangerous or delicate information across a border. Anyone actually with the possession of such information would obviously never bring any of it near the border control. However, I think the answer is that I'm way too optimistic. There must be lots of people who voluntarily do carry incriminating information with them across borders because they either don't care or they're just stupid. Others have mentioned emails or text about a job when you're not travelling with a work visa. If this is true then I think border control is also just being merely pragmatic. With a bit of questioning and informal profiling they can spot people whose story doesn't ring true: next they just need a way to figure out what's false with that one particular person. A success rate of 38% for electronics searches was quoted: that is very high and certainly makes mobile/laptop search to the top of the list of what to look at when you bring the traveller in and start investigating. I think they'd do it even for a 10% success rate: checking a few emails and messages is fast and apparently a low-hanging fruit. That's pretty much what I would do if my job was to figure out what's wrong with a person's story. It's akin to starting debugging by enabling asserts and running the binary in a debugger to catch any obvious issues live with a stacktrace, or something similar. Won't help with most of the trickier bugs but sometimes it points right at the culprit and it's a cheap test to run. They wouldn't find the folder containing your blueprints for that bomb but they'll see you'll be meeting some people next week in a place that is very, very far from where you said you'd be vacationing.