What do you think of Twitter and Facebook's censoring the Biden Ukraine story? ?

I think Twitter and Facebook are just trying to cover their own butts after being raked over the coals for allowing fake news stories to spread in 2016, potentially helping Russian propagandists manipulate the election that year.  The current NY Post story appears more fake than real.

These sites are de facto "news outlets" just like newpapers and TV stations.  As such, they have a perfect right and a practical need to edit their content.

The false notion that ANY "news" medium presents ALL content that it possesses to customers and allows the customers to choose what they will view is very misleading to people who haven't had any need to think about the BUSINESS of providing such content to consumers.  That's not how it works.

EVERY "news" outlet has access to much, much more information and material than its consumers will EVER see.  They ALL employ editors to "curate" their content - which ACTUALLY means "to choose what you will see and what you WON'T see, not with the goal of informing or educating you, but with the goal of maximizing the likelihood that you will turn to their particular outlet AGAIN".

It is misleading to confuse this editing process (which is inescapable no matter where you turn for "news") with "censorship", which is a slightly different thing.

You don't know if it's factual?  Let me clear it up for you.  Unfounded allegations are not "factual".  They are harmful and of course they should not be spread around. 

If you still don't get it, try this... Someone makes up something terrible about YOU and posts it.  Are you happy to let it stay on the internet or do you want it taken down so it doesn't give people the wrong idea about you for the rest of your life?

It's not censoring anything. It's them taking responsibility for the content of their social media platforms by not publishing what is unproven by any empirical evidence but to the contrary has been conclusively disproven with empirical evidence. 

If you think not helping someone spreading lies to spread their lies by repeating their lies for them to millions is censorship, then you're wrong, but even if you were right, that censorship wouldn't be a violation of the First Amendment because it isn't protected speech. To the contrary, it would be a fulfillment of the First Amendment as the First Amendment protects the right of Twitter's shareholders and Facebook's shareholders to have their websites publish or not publish what they choose.

What WOULD violate the First Amendment is the US government, including the President, forcing or trying to force the press or anyone to publish a story they've chosen not to and thus deprive them of their inalienable right not to.

By the way, it's not just Facebook and Twitter. It's all of 20 or so major social media platforms, along with all reputable major media outlets globally from Reuters to AP.

YOU don't know whether it's factual but, to the rest of us it reeks like an outhouse. Remember that Trump never asked for an investigation in return for our promised aid; he asked for the announcement of an investigation. Or maybe you DO know that it isn't and just want to earn your pay - - in rubles.

maybe they know

Why allow fake news when you know it's fake?