By trying to convince you of obvious nonsense, they've alerted you to their ill intent or simple ignorance.
The latter possibility is important, since believing in freedom, if it's to be popular, can't be wedded to a mind-set that easily see a lot of other people as being actively bad---that's the sort of world-view tht makes a lot of people reach for an Authority. And you in turn should wish to be given the benefit of a doubt; not everyone into whom you might bump should believe that you were trying to hurt them....