You bring up AT&T: are you talking about landlines or mobile? AT&T mobile probably could block hate speech from being sent across their private network in the form of texts. They would probably lose some customers to Verizon if they did, but they have that right. Landlines are a little different. You can't block hate speech being spoken across a land-line there are technical difficulties. The closest example would be if someone repeatedly harassed another person by ringing them up and making hate speech directly too them.
In this instance I am talking about landlines. I understand that the law isn't uniform across all mediums because the law hasn't kept up with technology. Excluding illegal activity such as harassment. No one is arguing that harassment should be allowed. I think much of the point of this conversation has been had before with landlines but that has fallen by the wayside because of new technology and a complicit government.
Facebook is not able to refuse service based on Race, Religion, National Origin, or Sex anymore than a baker can.
Actually, a baker can refuse service based on someones religious belief. but a baker cannot use their religion to influence their policy. The baker is unable to control their policy of use. Telecommunication companies cannot choose their policy of use, why should Facebook and Twitter be exempt from the same civic responsibility? Landlines were seen as critical in a modern society for citizens to participate. If social media companies are of the same criticality then they should have the same responsibility. If Obama and the Media are correct in 'Fake news' influencing the last election, doesn't that thrust those companies into the same stewardship position as landlines and bakers?
Sure, Facebook isn't denying you access to their service because you are Male or Christian, but they can deny you based on conservatism or liberalism because those are not protected classes. I guess, that means that the baker should have denied service because the gay couple in question were liberal instead of gay. Social media companies can overcome the technical difficulties you mention, does that mean that they are get to be arbiters of truth and politically acceptable speech when increasing number of citizens use their service? Is there any other service of such importance that we don't forfeit their civic responsibility? (important in that it can affect our elections like Obama has said)
You say I can go to Google+ but then why didn't the couple use a different bakery? If all of the social media companies have the same 'hate speech' policies that can ban ideology and much of the national dialogue occurs in those networks, on top of subsidized infrastructure, what will that do to our elections and society that wouldn't happen if telecommunications did the same thing to landlines? There are only so many options and not everyone can Zuckerberg their way a new Facebook.