I believe the distinction between the two (though note: I am very willing to change this belief based on learning details I don't currently know) is that Facebook tries to remove such content (though it may not perfectly succeed) whereas Parler actively refused to do so when AWS made them aware and asked them to remove it.

And the US government should bring a case against them. I don't think you'll find me inconsistent in that thought, I also argued an ISP yesterday that blocked FB is fully within its rights to do so.

Personally I think we need anti-trust action against a lot of larger tech companies and second that they have now opened the door on further regulation regarding content moderation. I think getting rid of Section 230 entirely would be a mistake but I won't be surprised to see it amended in some form.

Never mind plain old lobbying, any legislator who supports a crackdown on Facebook could be de-platformed. These tech leviathans have captured the regulators in a way that has never been seen before, and now they are flaunting grotesque anti-competitive bullying in all of our faces. Depending on the government to fix this mess is not going to go well.