and their contract, it seems like, says that they can police content.

It's still policing content. As a customer I didn't expect that they would for anything short of illegal.

Their interests are not the same as yours. That particular clause allows them to require the removal of content that places them at legal risk.

"Policing" incorrectly applies that they are actively trawling the site and telling people what to write about. That is clearly not true.

I see this sort of non-argument on HN a lot. Why do you believe that just because someone has the right to do something, that changes its nature? I have the right in the US to walk down the street shouting racist slogans. If I did so, should I be immune from criticism because it's within my rights? Is one magically not-racist just because the law says racist behavior is legal?

No-one's saying you should be immune from criticism, surely? FWIW: yes, you should totally be able to say whatever you want, even if it's bigoted, flat-out wrong, outdated, whatever; as long as I'm free to say that it's dumb and bigoted, flat-out wrong, outdated, whatever ;)

I think you're perfectly within your rights to criticise Digital Ocean. And I am perfectly within my rights to argue about the nature of Digital Ocean's actions.

The others, to clarify, in that case being: a court.