Sponsored news stories — or what are more politely known as native ads — are becoming a fixture of the web, yet it isnt always so easy to tell when an article is sponsored. Google engineer Ian Webster is now trying to solve that problem with a browser extension called AdDetector, which searches out native ads and drops a bright red bar over the top of the page announcing that what youre viewing is a paid promotion. Its been set up to work with a close to 50 sites already, including The New York Times, The Wall Street Journal, BuzzFeed, several Gawker Media sites, and two Vox Media sites, including The Verge.