This browser extension works by collecting the full contents of the page the user is currently viewing and uploading it to a server-side component.

Only pages within a whitelist of websites (mostly news websites) are collected. No other pages are affected by this extension at all.

The server uses the uploaded page contents for matching it against a set of Wikipedia pages that are known to need references. The page contents are not stored, but the URL and search results may be. No personally identifiable information is collected or stored.

Both the extension and server are open source (licensed under the MIT license) and their full source code can be found at https://github.com/eggpi/similarity , including the list of whitelisted websites for which data collection occurs. Additionally, the server is hosted at Wikimedia's ToolForge infrastructure, and as such, is subjected to the following terms of use: https://wikitech.wikimedia.org/wiki/Wikitech:Labs_Terms_of_use .