I’m old enough to remember when Judas Priest (the 80’s rock band) was accused of hiding subliminal messages in their songs convincing their listeners to commit suicide, after a kid did so while happening to be listening to Judas Priest. It seems absolutely ridiculous in hindsight, but people believed it, and it was taken completely seriously at the time: https://www.rollingstone.com/music/music-features/judas-prie.... The logic here is essentially the same: some internet message boards are “egging somebody on” to do something that they would not otherwise have done, which results in death, so the internet message boards themselves are to blame, and must be censored.