I have leaf damage that looks exactly the same and I always see these fuckers crawling around my plants! They're not overwhelming though. I usually find 3-5 of them in the room each day and I just smash those fuckers! Damage seems to be pretty limited... only a 1-2 leaves I've seen. It almost seems like they like the warmth of the lights more than anything. They're never eating when I show up... but they do seem kinda smart for bugs. They definitely sense your presence. As I was just snapping a picture of one it fuckin' tensed up...
Man, we had a huge infestation of these things when I was a kid at our house. They would gather in INSANE numbers on the side of our house that was warm... my mom always made me go out and spray them with soapy water to kill those fuckers.
Anyway, bottom line, I don't think they're too much of a problem. I am a little worried that they'll be harder to spot when plants are bushier, but it should be warmer by then and hopefully they'll be heading outside.