Wikipedia
WhatDoTheyKnow is a site by mySociety designed to help people in the United Kingdom make Freedom of Information requests. It publishes both the requests and the authorities’ responses online, with the aim of making information available to all, and of removing the need for multiple people to make the same requests. The site acts as a permanent public archive of FOI requests made through it.
Around 15% to 20% of requests to UK Central Government are made through WhatDoTheyKnow.com. Over 16,800 public bodies have been added to the site, mainly by volunteers. More than 294,000 requests have been made using the site and more than 4.5 million people visited it in 2014
WhatDoTheyKnow has been described by The Guardian as "an idiot's guide to making a freedom of information request." The Information Commissioner's Office has stated that it believes "the most up-to-date informal list of all public authorities is held on the website". Information released through the site has given rise to serious and less serious news stories. The site is used by a number of MPs.
The site was originally available only in English but a partially translated Welsh version was added in 2013.