No microwaves around, this happens in different locations. But a good point, indeed. And I don't work or live in a radiotower or anything like that :-)
Butterfly: yes, indeed when flicking through desktops a few of the same horizontal black quick lines appear if I try a couple of times, but nowhere as much as when an "attack" occurs; they're everywhere then, I would say there are at least one line per screenupdate, probably more. 50 black horizontal lines in different places per second? Perhaps. There's a lot of flickering going on. And right now, nothing, the screen is calm and nice, and I haven't found a way to start this flickering-attack intentionally - yet.