Wikipedia built its encyclopedia empire (or, really, encyclopedia democratic republic) by ensuring that anyone with reliable information from anywhere can contribute. The question, of course, is what “reliable” is. One thing it’s not: the Daily Mail. In the culmination of a discussion started back in 2015, Wikipedia editors have decided that the English tabloid no longer constitutes a reliable source for article information and have issued a ban on using articles from the Mail, or its online version, to source Wikipedia pages.
Consensus has determined that the Daily Mail (including its online version, dailymail.co.uk) is generally unreliable, and its use as a reference is to be generally prohibited, especially when other more reliable sources exist. As a result, the Daily Mail should not be used for determining notability, nor should it be used as a source in articles. An edit filter should be put in place going forward to warn editors attempting to use the Daily Mail as a reference.
As noted by Wikipedia, much of the information found in Daily Mail stories (and often sensationalized in Daily Mail stories) can be found in other publications. Currently about 12,000 DM stories are linked and sourced throughout Wikipedia, and editors are being asked to consider replacing those. The new ban has a few exceptions where editors can continue using DM content, specifically in cases of older and potentially more reliable articles.
Wikipedia banning the Daily Mail is the first time the website has placed such wide-ranging restrictions condemning a single source. Even Russia Today, a Kremlin-sponsored propaganda website is still allowed for sourcing, which definitely says, uh, something about the state, or at least the style, of the Daily Mail in 2017.