This is not what i am refering.
What i think of is logging in a faction, look if i am the only one there or if there is more, (at least 2-3 people) then log-off. So i would know that, if i am triggening something in the core, i could hope for PVP or not. The fact there are people don't mean they will come. But the fact they aren't there mean i am 100% sure they won't come, so no need to bother. If this is what we are talking about, it is fair and it is consistent with the goal mentioned by Piggy.
If it is standing near the grid, see how many people gathered, how much time it took them, what weapons they have, what they are saying to each other, what is their plan, then wait for them to leave, see the squad grid to check in which map/zone they are, then go in said map and check for their position, then log off and call the strike on this position, this is a not defendable at all, it is outright spying and it isn't consistent with Piggy previous explanation.