Guess I'd be curious if there's a way to prove to someone they're not being targeted.
Judging by the comments in StalkinVictim's video, this is typical: the "victims" have no idea why they are special to the stalkers, but are quick to jump to conclusions anyway. To me this is a form of alienation and possibly mental illness. They see the patterns they already expect to see.
Each day I take the subway I look at random strangers, and random strangers look at me. When someone stares at me longer than normal, I just assume they are either lost in thought (and just happened to rest their eyes on me), or my hair looks funny, or they like my clothes, or maybe I resemble someone they know. People with paranoia tend to think they are being stalked, which is the least reasonable assumption to make.
I suppose there is no way you can prove to them they aren't really being stalked. They base their assumption on the flimsiest of evidences; it's their brain that's making the unwarranted connections.
Believing that you were randomly selected for a form of psychological terror that would take enormous resources from the attacker is a pretty clear sign you are delusional.
This is a group of people with mental health issues that unfortunately also self sustain by suggesting relatives are "in on it" and that seeking help is bad.
Only way this might be similar is if for training or testing reasons that someone randomly became the subject of some effort. Given the resources this would take, such efforts would be short in duration and likely near known R&D or training spots for entities that would engage in things like that.