I believe I understand this ACLU stance, and the comments that agree with it. I suspect, though, that those in other countries, as I am, might look at it differently, particularly in other democratic countries that have more restrictions on what is and is not permissible regarding “free” speech.
The concern I have is that I think fringe groups (extremist and potentially violent messages) reach and convince new converts via the repetition of the hate filled agendas they put forth, whether it be paranoia about government, or immigrants, or people of color, or women….etc.
The Internet has provided unfettered reach for these groups, and it is indeed the case that the MORE that impressionable people are exposed to the same messages, the more it seems they contain truth. That might not effect those less susceptible, but it does allow for recruitment.
And let’s remember that people can still create their own platforms to present their hate speech (within the law), so Facebook (however inept they might be) is not impinging on their free speech — just their ability to look for recruits on Facebook.