Twitter comments, straight up. I would say the average IQ of a tweet is very very very low. People write and don't even ask themselves " is that worth writing ?" "I am not wasting absolutely everyone's time ?" "Am I not saying the most absurd thing ever just to get some likes ??" I don't know but sometimes I sigh so hard reading those comments that my mom asks if i'm good. To be fair, some tweets are clever, informative or fun but the comments never seem to be smart.
That's why I don't read them anymore, I feel like I loose braincells..