Google already hopes to prevent security threats in Chrome by blocking downloads, and it's now planning a similarly cautious approach for extensions. The company has announced that all extensions for the browser's Windows beta and stable versions must be hosted in the Chrome Web Store as of January. While developers and corporate users will still get to install add-ons from local sources, the rest of us will have to go through the official portal. The safeguard should reduce the chances that deceptive extensions hijack the app, according to engineering lead Erik Kay. Google tells us that there aren't any plans to put similar limits on other platforms, since most complaints about bad extensions come from Windows surfers. The policy could go a long way toward protecting Chrome, albeit at the expense of choice -- developers who don't want to go use the Web Store will soon be out of luck.