Corbin Davenport writes: “Web browser extensions can turn from useful to dangerous in just one update, potentially opening up your browsing habits and some personal data to an unknown third-party developer or company. It has happened over and over and over again, despite the best efforts from Google, Microsoft, and other browser developers. Free browser extensions usually rely on donations, open-source contributions, or affiliate revenue to subsidize the cost and time involved with development. However, sometimes the developers look for ways to generate additional revenue without charging the user, which is where we start running into trouble.”