Sci-Hub

Sci-Hub is a shadow library website that provides free access to millions of research papers and books, without regard to copyright, by bypassing publishers' paywalls in various ways. Sci-Hub was founded by Alexandra Elbakyan in 2011 in Kazakhstan in response to the high cost of research papers behind paywalls. The site is extensively used worldwide. In September 2019, the site's owners said that it served approximately 400,000 requests per day. The number of articles claimed is frequently updated on the site's home page, being over 85 million in February 2021. Sci-Hub and Elbakyan were sued twice for copyright infringement in the United States in 2015 and 2017, and lost both cases by default, leading to loss of some of its Internet domain names. The site has cycled through different domain names since then.