> Internet firms in America are shielded from legal responsibility for content posted on their services. Section 230 of the Communications Decency Act of 1996 treats them as intermediaries, not publishers—to protect them from legal jeopardy.

> When the online industry was limited to young, vulnerable startups this approach was reasonable.

That's the wrong way to look at it. The size of the company should not matter here. It's how they operate that should determine which regulation applies to them. There are only two reasonable alternative:

Either they are intermediaries, in which case they should have the duty to indiscriminately intermediate whatever they are asked to intermediate. This means no centralised moderation. Maybe allow moderation at the sub-community level (as Reddit does with its subforums), but no centralised censorship, except maybe upon reception of a warrant.

Or they are editors, in which case they should have full legal responsibility of the content, and suffer full legal consequences of whatever illegal speech they allowed.

I believe such a clean dichotomy is the only way to ensure free speech in the face of such centralised services. 'Cause I think the likes of Facebook, YouTube, Twitter… would rather choose the "intermediary" path than risk taking legal responsibility for their enormous user base.