And its easy to bypass.
Exactly. The criminals will know how to by pass and avoid all the hassles. Meanwhile...
No offense but welcome to legislation in general. Look at gun control, nobody really thinks the criminals are willingly giving up their guns either, but they make those laws. Like I said in the post you quoted (but you cut that part out), I'm not a fan of them rifling through my bag but I still don't see how this is really any different. Maybe they would spot your anti-fungal crotch cream in your bag, and maybe they would find evidence of an affair in your laptop. Same type of stuff...not illegal, but emberassing.
I'm just not seeing where this is any different...especially since the only feasible way to search it quickly is to let a computer do the search and then nobody actually sees whats in your laptop....hell if thats the case I think this is less of an issue than the bag search since at least then the details of your personal life aren't floating around in someone's head.
Now if they copy/save the data from laptops that are cleared to proceed then I will have a problem with it since they should have absolutely no reason to keep such records...otherwise why did they clear them?