Here's a useful piece of advice right up top—don't use a free VPN. Many will have serious caveats, as demonstrated by the security researchers at Koi, who say they've discovered a particularly popular Chrome-based variant taking unauthorised screenshots and spying on its users.
The accused Chrome extension is called FreeVPN.One, and it's currently sat at 100,000+ downloads on the Chrome Web Store—complete with a coveted "featured" badge that supposedly marks its compliance with recommended practices (via Sweclockers).
