I fantasize all the time about buying stuff like this and using it for nefarious purposes.
Unfortunately the only real legit use for it is boring security work.
The best way to use this while avoiding big legal trouble would be to stalk a single target that would never have any idea they are being stalked and doesn’t have much resources to come after you legally. Maybe an ex-girlfriend or something.
Would they really need many resources to take legal action? What you're describing is illegal. They could simply call the police if they found you out.
Unfortunately the only real legit use for it is boring security work.
The best way to use this while avoiding big legal trouble would be to stalk a single target that would never have any idea they are being stalked and doesn’t have much resources to come after you legally. Maybe an ex-girlfriend or something.