Yep. The last few times I've been through London they've insisted on absolutely emptying my backpack because, and I quote, I had "carefully coiled cables in it". I'm an IT guy, I travel with a laptop, several devices for entertainment on a plane, chargers, etc. I promised them that next time I would toss the cables in haphazardly so as to prevent further issues. They were...unamused.

And god forbid you had a drop of liquid inside, as they will swab every nook and cranny of you bag and put the samples through some kind of detector.