With +50.000 subscribers to the subreddit SCHOLAR https://www.reddit.com/r/Scholar/ it is for sure a network to be mentioned, when talking about the various existing ways to get to full-text.
If i am honest, i did not know about it untill recently i read a blog post by Aaron Tay (Reminder: you should ALWAYS read ALL his posts!
Musings about librarianship)
)
Basically subscribers of this “subreddit” (the amount doubled since Aaron wrote his post btw) request the full-text of an article or book (mind you there is also a specific reddit for “bookexchange”