Online groups can and do influence people's thoughts and beliefs over time. Just my own anecdotes, but I've seen people completely turn against those in their lives who were obviously well meaning and supportive, because of baseless anger and fears which seem to have come from nowhere. And then it comes out that they were actively reading online groups that encouraged and normalized these anxieties and rage, condemning those who common sense and anyone else can plainly see are active forces of good in a person's life.