A balloon is in your airspace. It is very different from a satellite in that respect. There’s a good reason shooting satellites is seen as a bad thing™. Shooting a balloon… eh, difficult target but good practice otherwise.
Why a balloon and not a satellite? Well you can’t surprise anybody with a satellite. They are on a schedule and it’s well published. “Time for the three o’clock boys, tarp 'er up!” That balloon however suddenly shows up and might catch something out in the open. Bit like having a signal sniffer in a corn mill might too.
These balloons are often enormous - 100+ meters wide, and can be hard to shoot down. There was a notorious incident where a Canadian weather balloon went out of control in the 90s, and the Canadian and British air force were unable to force it down, even after pumping it full of thousands of rounds. They had to wait for it to land in Norway.
