5 Alternative ways to get scholarly material that don't involve your library

I always been fortunate to be associated with a institute with a good academic library so I haven't really kept up with illegal or semi-illegal ways of getting access to scholarly material.

Still I've been recently thinking about the amount of free scholarly material available online and the amount of it that is legally or otherwise available and how they stack up against library document delivery.

The 5 methods are

1. Search for free copies via web search (mainly Google or Google Scholar)

2. Requesting copies from authors (via Institutional Repository or Social networks like Academia.edu)

3. #icanhazpdf requests on Twitter

4. https://www.reddit.com/r/Scholar/ on reddit

5. Illegal sources like Libgen and/or sci-hub.org

How effective are each of these methods?

To read on.......