Law professor Eugene Volokh has a good read on the topic here.

According to him, the tech companies are playing very fast and loose with that particular law, which is the Communications Decency Act. The part that gets abused is
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material that the provider or user considers to be obscene, lewd, lascivious, filthy, excessively violent, harassing, or otherwise objectionable, whether or not such material is constitutionally protected;
The misconstrued phrase is "otherwise objectionable" which the tech companies have interpreted as a license to censor anything they don't like. That's not what the law says. What it says is that they can censor stuff that is on the list and "otherwise objectionable" material that is similar to the items listed, and which fall within bounds of the Communications Decency Act. Very little of what they censor meets the standard.

A day of reckoning is coming. It will be grand to watch.

Be not weary in well doing.