Having worked as a researcher all my life in academia (but not in the industry), I can not support Sci-Hub. I know it's an unpopular opinion but I think it's the wrong approach.
As scientists, I think we should be held to especially high moral standards. And there are two questions one should be allowed to ask:
1. Is is right to publish research results funded by tax money behind a paywall?
2. Is it right to circumvent a paywall to access publicly funded research results?
And to me, the answer to 2. is imply 'no'. I know that most people, especially here on HN, do not agree with that view. Perhaps they might think that a 'yes' would immediately follow from a 'no' to question 1.
But I don't think it does, and I'm not even sure my answer to question 1 would be a 'no'. Perhaps one could think about another question first: should researchers turn to a professional publisher to get their research published, and I think at least some years ago there wasn't much else you could do. Now, of course, there are digital platforms such as arxiv but their acceptance also depends vastly on your field. In any event, such platforms can also be thought of as a publisher, anyway. The main service provided is organizational: publishers don't review the research contents (they're not qualified for that) but they organize external reviewers; publishers provide discoverability because they are a well-defined source known to the community. Are there alternatives to that type of work? Sure! But there is an added value in what a publisher does.
So then in a follow-up question, we can ask whether a publisher should be compensated for their work. And to me, it is pretty clear that they should be. Of course, there are different ways this could be implemented but that decision is up to the one running the business, ie., the publisher. I can think of more customer-friendly ways than to make me pay for every single download of a paper. On the other hand, there are lots of other businesses where I don't like the way they make money - tough luck for me, I guess.
Now, I think this last point is very important, especially before you go and hit that downvote button (unless you already have): I can think of better ways (for me!) how research publishing should be realized. But I don't think that from that it follows that I should be able to or even have the moral right to circumvent publisher paywalls.
Perhaps it's wrong to charge for access to publicly funded research results but I don't think the second wrong of circumventing publisher paywalls makes that right.
Oh, and here's a little subtlety I don't see discussed very often: if I do research funded by UK tax money and publish it, should that paper be freely available to Americans too, or only to UK tax payers?