If magazines, newspapers, movies and TV stations are liable for what they publish why shouldn't social media also be?
The "but it is only transportation of information, like telephones" argument is just ridiculous. It is valid for email at best, it is not valid for social media. They already routinely practice filtering of what is posted.
We shouldn't expect the U.S. to advance this cause. Their congress is too deep in the pockets of lobbyists to be accountable to public interest. It has to come from the E.U. and responsible governments.
Edit: this is a repetition of history. There are a lot of tragic examples of tragedies sparked by publications meant to extract profits from people's paranoia and fear. The most famous one is the witch hunt started by the book Malleus Maleficarum[1] that caused more than 30 000 deaths. We created means to contain these abuses in new media too. The genocide of Rohingya people could have been avoided if Facebook were liable for it.