I can confirm this because this is my experience. There was a public place that I used to visit. I visited this place randomly only a few times a year when I needed to read in quite. When I started noticing things in my life I began paying more attention, and the following time that I visited that place, right after I entered, behind me came in a group of individuals who appeared to not be together but were all dressed the same way I was dressed. That is the first time I noticed. I ignored them after that, but they persisted in their fear mongering around the places I frequented. They do it in subtle and distinct ways that most would not care to pay attention to or notice. It is without a doubt a cooperated act between an organized group that communicates and coordinates, and it couldn't be achieved any other way. It is a mob or group that targets individuals and stalks/harasses them.