Soros et al. can do far worse than censor Steemit. Consider that a sybil attack on a blockchain simply requires that a majority of nodes producing blocks collude. In Steemit SP acts to produce a mathematically identical mechanism potentiating control of SP: the more SP you have the more influence you have on the distribution of SP.

Presently over 90% of rewards inure to a handful of accounts (I have been unable to get post HF19 data to precisely characterize this concentration to compare with this prefork data that shows 99% of author rewards went to 1% of accounts) and this dominance is predicated only on wealth.

This is an Achilles heel that will not persist for much longer. I recently replied to a commenter that stated he was self voting because Steem had crashed and reduced the value of his holdings by $50k, to ~$150k. I pointed out that BTC had recently been $3k, and were Steem to be but 1% of that price, he would achieve capital gains of $4,350,000. Mining the rewards pool hardly compares to that return, and it is only a matter of time before control of SP is attained by hostile capital (if the code continues to permit it).

Oddly, the most profitable course is to make rewards fairer, as this best potentiates capital gains, which is far more potential of significant returns than mining curation. However, voting on witnesses can change this by changing the code, and smarter people than I will take advantage of this possibility, when they get around to it.

To my dismay, this may already be in process, as HF20 is intended to exponentially increase adoption of Steemit, and the only thing in the way of an enormous pump and dump is the 13 weeks necessary to power down.

Since this is trivial to change, Steemit's vulnerability is existential.

$30 Steem isn't that far away, and the financial manipulations that suppress Steemit's growth by concentrating the rewards, that are intended to support content creation, in the accounts of substantial investors in Steem, is probably the main reason that Steem isn't bucking the general crash of cryptos. Steem is unique amongst the cryptos in it's use case, which potentiates unimaginable capital gains (far greater than I have treated here).

Since all it takes to control the rewards pool distributions is money, Steemit, and Steem, are very vulnerable to hostile takeover. The code could easily prevent this, and I hope that the codebase does soon preclude such attacks, rather than potentiate them.

As you point out, it is similarly trivial to make posts all but invisible with sufficient SP backing your VP, and I am not incognizant of the likelihood that this kind of information will be found inconvenient in the near future. Only changing the code to preclude the very control of rewards (and post visibility) by the wealthy can protect that wealth from even greater wealth.

This seems to be beyond Steemit's PTB presently, as far as I have ascertained in my discussion of the topic.