> The immunity must be limited to sites that are neutral, in the same way that non-political religious organizations are tax-exempt. Why? Because to claim that a site isn't responsible for a user's content is fine, until the site starts editing, censoring or weighting certain points of view. When the site loses its neutrality it ceases to be a conduit of content and instead becomes content. Indemnification from liability for a specific point-of-view is, I feel, an abridgment of free speech and I believe it is unconstitutional.
1) Yeah that works great until someone uploads content about children being sexually abused and you can't take it down because taking it down is a non-neutral action (censorship).
2) Same, but non-consensual pornography of someone's ex.
3) Same, but advocating a clear and immediate desire to commit violence.
4) Same, but "fighting words" (a well known exemption when said to someone's face to free speech protections).
5) Same, but obscenity.
There are some very, very massive flaws of that nature with your position and I'd continue but I think you are getting the idea. Such things don't only impact the speaker and therefore create a situation where the provider should (in theory) censor them.
Similarly, such things have been ruled to be outside of the bounds of "free speech" in the US by the judicial system.