ClearURLs is a browser extension that automatically removes tracking elements from URLs, which according to the developer, helps to protect users' privacy.
Many websites use long URLs for tracking purposes, including Google.
Extra parameters in long Google URLs are used for analytics.
"ClearURLs has made it to its mission to prevent tracking via URLs and that's how Google makes money. I think that ClearURLs now has so many users that it is unwelcome for Google and they would like to see the addon disappear permanently," - said Kevin Roebert, the ClearURLs developer.