I've got to think it's easy to find starlink receivers--I know they use a directed beam but they must give off a bunch of lateral noise, right? Or does Starlink use the same frequency bands as other common equipment such that it would be difficult to distinguish starlink signals from others? If the government was motivated they could surely start finding these receivers, right?

Well the better your beam is directed, the less lateral noise there is.

A simple 3 element yagi has <1% of the power to the sides. It has more of the power straight behind it, but still 1% or so of the main lobe.

From what I read, the Russians were targeting Starlink terminals based on the built-in wifi access point not the Starlink frequencies.

I read the satellite has an omnidirectional antenna?