Primarily because very light harrassment isn't generally illegal and won't typically get you arrested. You'll be hard-pressed to get someone to care about that.

Primarily because very light harrassment isn't generally illegal and won't typically get you arrested. You'll be hard-pressed to get someone to care about that. The Beijing reps are surely careful about the extent of it, about not going too far, in most cases. Since the target likely knows who they represent, they don't have to press too far, they just have to make their presence known and it's enough to terrify without any specific act of violence or threat occurring (which limits what the police & co. can or will do). And last but not least, does the target want to ramp things up further with Beijing by pursuing it criminally, trying to get a restraining order, and so on. If the target succeeds, Beijing can just send more. It's lose, lose, lose, every direction you turn when a superpower has marked you and you lack any consequential power. Much like the IRS trying to battle the Church of Scientology, they have an army of followers willing to sacrifice themselves for the cause. How do you fight that, other than for the Feds to get involved and start removing these people from the US by the hundreds. It wouldn't surprise me if the Feds just follow & watch on purpose for intel acquisition purposes.