At least some of them have been pirates for me in the past, but it's possible that's changed recently, certainly - I've spent relatively little time on planet surfaces in inhabited systems the last couple of years. (Planet surfaces yes, inhabited systems yes, both at once not so much)
Definitely more for the ship scans part than the wake scans, agreed. Though they do sometimes jump out and you can pick up a high wake on the scanner at a much greater distance than a ship.
I'm fairly sure that ship scans are not going to be particularly high scoring, and "someone hanging out on a planet surface scanning ships for a week" is not going to be relevant to the final result in the system. If Power NPCs stop appearing there, I don't think it'll be a problem at all in practice or a meaningful exploit opportunity. If it's that big a deal they can take out the cosmetic non-power NPCs too, no objection from me.
But equally, the way PP2 has been described and previewed so far, it doesn't seem to have much concept of "pledged but not doing anything right now" unless you get clear of the bubble entirely - if you're in a system controlled by another Power, you're probably doing some harm to their standing unless you're very careful to deliberately avoid actions which might. That seems to be very deliberate - Frontier certainly didn't have to include "scan ships" as a PP-scoring action, since it does nothing in BGS! - so at least for the first few weeks, having Power NPCs show up and shoot at people just to get them out of the PP1/BGS mindset of "I am harming the local authority's interests in a major but perfectly legal way so I am safe from retaliation" is probably a good thing.
Yes, for Elite Dangerous, this is weird. We're all used to a High Intensity Combat Zone be a perfectly safe place to be (until you pick a side), and then once we get out of that having personally killed 10 ships we get a minor rep hit and then it's all back to "hello valued friend please dock at our station for repairs and resupply" from the faction we were just shooting. We're all used to being able to shoot down pirates in RES all day without our rep with the local Anarchy faction dropping below max-Allied for a second. There's the occasional "what?" from new players about Admiral-King CMDR Fred but the rest of us just handwave it as "well, of course it's absolutely fine to be a renowned double agent for both sides, it's not as if the ranks actually mean much".
Powerplay 2 breaks away from that by making the sides you oppose actually take it personally for once. It'll take some getting used to.
