I am not defending the current state of academic publishing, but I feel this needs some clarification: Sci-Hub hosts information that belongs to publishers, not scientific/academic institutions. The original academic papers are available from the institution that funded the research, but not these curated/peer-reviewed papers as published in academic journals. It's not knowledge they're trying to hide... publishers (just like any media outlet) get testy when their stuff is "stolen" and they don't make money.