As many as 4 million people have been leaking personal and corporate secrets through Chrome and Firefox, And that’s just the tip of the iceberg,. The root of this privacy train wreck is browser extensions. Also known as add-ons and plug-ins, they’re little programs used by nearly half of all desktop Web surfers to make browsing better, such as finding coupons or remembering passwords. People install them assuming that any software offered in a store run by Chrome or Firefox has got to be legit. “Not all of these companies are malicious, or doing this on purpose, but they have the ability to sell your data if they want,” Extension makers sometimes cash out by selling to companies that convert their popular extensions into data Hoovers . So why aren’t Google and Mozilla stopping it? Researchers have been calling out nefarious extensions for years, ?