I have young kids and spend a lot of time in playgrounds. When I push the swing a flat earth believer approaches me to tell me about chemtrails , flat earth a

I have young kids and spend a lot of time in playgrounds. When I push the swing a flat earth believer approaches me to tell me about chemtrails , flat earth and how vaccines cause autism. He brought pamphlets about vaccines a few times. Always citing some Harvard Prof who supports his theories and refers me to YouTube. He has a little girl that he pushes on the swing and talks to everyone he can about vaccines. That's a really damaging. I just want to politely stop this conversation, though I enjoyed the flat earth stuff. His talking to new moms about vaccines is potentially damaging.