Wikipedia has received praise for its enablement of the democratization of knowledge, extent of coverage, unique structure, culture, and reduced amount of commercial bias, but criticism for exhibiting systemic bias, particularly gender bias against women and alleged ideological bias.^[13][14] Its reliability was frequently criticized in the 2000s but has improved over time; it has been generally praised in the late 2010s and early 2020s.^[3][13][15] Its coverage of controversial topics such as American politics and major events such as the COVID-19 pandemic has received substantial media attention. It has been censored by world governments, ranging from specific pages to the entire site. Nevertheless, it has become an element of popular culture, with references in books, films, and academic studies. In April 2018, Facebook and YouTube announced that they would help users detect fake news by suggesting fact-checking links to related Wikipedia articles.