Twitter has no business inserting itself into a dispute between Elbakyan and Elsevier et al. Few people would have issues if Twitter shut down the Sci-Hub account after they received a valid court order, but a private monopolist cannot be trusted to be the arbiter of what is permitted speech.
It all boils down to this: a) Should twitter be allowed to cancel accounts who harm twitter? If yes: b) Who decides which accounts harm twitter? If the answer is "twitter", then they have effectively the right to terminate any account at their will. I don't know what other answer is possible for b) except maybe "the courts", and I'm not sure I like that one. If the answer to a) is no, for which companies does this ap…
Regulated public utilities generally speaking can't just drop customers simply because they feel like it or don't like them or view them as a "threat". Thankfully the electricity company can't just disconnect you because they don't like you. So long as you pay the bills, they have to keep you on as customer. (I think they can disconnect you if you violate technical rules about electrical safety, such as trying to draw more power from the network than your connection is authorised – but they can't simply do it because they disagree with your politics, or because you are charged with a crime no matter how heinous, or because some third party is suing you, or so on.)
And there is an argument for regulating Twitter/Facebook/etc as public utilities.
A lot of people in Australia's conservative ruling party are pretty upset at Twitter. They were asking Twitter to take down a faked image of an Australian soldier slitting a child's throat which was posted by the Chinese government. Twitter refused. Then Twitter banned Donald Trump. Twitter will argue that the two situations were very different, but a number of conservative Australian politicians don't agree. They are calling for government regulations to control when Twitter can remove content or ban people [0]. Effectively, turning it into a regulated public utility, at least in Australia. (If the Australian government goes ahead with this, I can't see any way out of it for Twitter except to either comply or block everyone in Australia from accessing their service.)
[0] https://www.smh.com.au/politics/federal/threat-to-democracy-...