While a protocol may not care, jurisdictions do have a say as to what is transmitted over them. A mailbox doesn't care what's put into it, but it's illegal to send a bomb throw the mail.
I think your argument with respect to Facebook attempting to be a utility is interesting, but I'm not sure how true it is, and whether that actually implies no restrictions. Utilities are generally subject to regulation. Edit to add: One can discuss what form that regulation should take and what it's limits should be, but that's different from saying there should be no limits.
If you think people shouldn't be allowed to say certain things, you need to be going after the people saying those things, not the technology they're using to say it.
I think here is where a potential misunderstanding is. I've said nothing about "people shouldn't be allowed to say certain things", I've been asking purely about whether or not there should be regulations or items removed from a site, including illegal material. If I'm understanding you correctly, you're looking at this purely as a censorship issue. There's a difference here, and one that's worth at least acknowledging. For example, if someone is posting something that is illegal, the appropriate authorities will both remove it from the post and attempt to go after the persons responsible for posting it, whether that's online or in the real world.
There's room for discussion, but first we have to figure out exactly what where' discussing, otherwise we're just taking past each other, and accomplishing nothing.
I think your argument with respect to Facebook attempting to be a utility is interesting, but I'm not sure how true it is, and whether that actually implies no restrictions. Utilities are generally subject to regulation. Edit to add: One can discuss what form that regulation should take and what it's limits should be, but that's different from saying there should be no limits.