Yes, very true. The “enforced positivity” practiced by Facebook makes it impossible to voice an opinion that isn’t overtly ‘nice’ and that’s not how humans normally behave offline so it amounts to FB basically shaping human behavior. Add to that the echo-chamber effect and this becomes a real problem. If a disturbed individual has his or her potentially destructive worldview constantly reinforced and the only option for peers or others who see the danger over the horizon to send a quick reaction is to “like” their twisted notions. This is a glaring problem. Offline if a person told you they wanted to harm people you certainly would not say “oh, I like that!” Facebook and other social media outfits should address this but likely won’t because it interferes with their business model.