When someone posts obvious misinformation he's downvoted to oblivion fairly quickly, and when someone makes an honest mistake he's corrected by people who know better and hopefully update his views adequately.
My hopeful attitude is that none of us are so fragile and gratuitously impressionable that this would be dangerous.
My further hope is that anyone that might be so impacted would incorporate the digestion and (eventual) repudiation of this information as part of their intellectual maturation process.
My final hope is that we all learn how dangerous and stifling it is to hand over defining and legitemising "truth" to others. You need to learn and grow as an intellectual being and that doesn't come in a hothouse protected from all perturbations.