Earlier quoted context omitted.
I have one in my work browser to redirect a journal’s website example.com to example.com.library.university.example.net in order to get the full access. Having a simple button for this made my life a lot easier, though I admit that it is somewhat of an unusual case.
You can admit it: it’s sci-hub
Actually, no, the library-provided full-access website for APS journals is much nicer. If I want a preprint, I can usually find it on arXiv and last time I looked at it, I found sci-hub to have a rather confusing interface.