Sure. But if you geoblock all use on Russian controlled land, you're also blocking Ukrainian use on Russian controlled land. I have no idea if that would cause issues or not, but it's not that far fetched to imagine it might.
I know this is a meme but for those at home the whole point of a war is to cross over the front line into the opponent's territory and capture it. If your comms are disabled when you cross the front you can't really fight. So "just disable Starlink within Russian territory" does not solve anything.
You can have a hybrid approach - deny access in that area by default but have a secure way to whitelist specific terminals for short periods (mission duration)
The issue isn't Russians using Starlink inside Russia (they have other option, e.g. wired system, etc. there); the issue was their using it for drones and other combat operations inside Ukraine (including Ukrainian territory presently held by Russia).
It's beyond sickening what none of you even bother with the idea what a civilian service should not be used by the military, especially in the zone of the conflict - by any side.
SpaceX is a privately-owned defense services company. Their #1 client is the United States. Their launches out of Vandenberg occur because the United States Space Force allows them to happen.
Are you on their board? Who are you to make the call that the product they are offering is a "civilian" (only?) service?
It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation.
I think what's actually funnier is that the satellite shooting the laser has to know where the terminal is with pin point accuracy too. So it's pretty easy to cut off targeting to a vast chunk of the planet.