The most likely way to end the free internet would be to make ISPs responsible for the content they serve and deliver.
Think about it.
If they could get sued for presenting libelous content or sites that accidently had users promoting terrorism,
they would require a license for anyone to post.
More than a license, they would require insurance and security bonds.
There would likely be some exceptions for liability for sites that had 24/7 moderation and could quickly remove contenty but an unknown couldn’t have a website or update content without some ISP review.
The scary part, is that with the “Fake News” hysteria on the left, and the desire for control of all things on the right, we really might see the end of the free internet sooner than we think.