Everywhere you go online, you're being tracked. Almost every time you visit a website, trackers gather data about your browsing and funnel it back into targeted advertising systems, which build up detailed profiles about your interests and make big profits in the process. At the end of last year, thousands of websites started being more transparent about how many companies your data is being shared with. A WIRED analysis of the top 10,000 most popular websites shows that dozens of sites say they are sharing data with more than 1,000 companies, while thousands of other websites are sharing data with hundreds of firms. Quiz and puzzle website JetPunk tops the pile, listing 1,809 "partners" that may collect personal information, including "browsing behavior or unique IDs." More than 20 websites from publisher Dotdash Meredith"including Investopedia.com, People.com, and Allrecipes.com"all say they can share data with 1,609 partners. The newspaper The Daily Mail lists 1,207 partners, while internet speed-monitoring firm Speedtest.net, online medical publisher WebMD, and media outlets Reuters, ESPN, and BuzzFeed all state they can share data with 809 companies. DuckDuckGo keeps a record of the companies that have the biggest tracking footprint across the web. Among the most common trackers, Google has its technology on 79 percent of websites, while those from five other companies are on more than 20 percent of websites.