Virtual private networks are great for a lot of things: protecting your passwords when you hop on public Wi-Fi, accessing your favorite Netflix shows when you travel out of the country, and aiding and abetting you in the criminal act of reading Wikipedia where it's been outlawed. But in the midst of growing VPN hype and a booming market, it's important to understand how VPNs work and examine vendors with some skepticism, keeping in mind a few things VPNs can't do.
Let you game at work without the boss knowing
Unfortunately, a VPN isn't going to shield your binge-watching from the boss' gaze if your company is large enough to have a fleet of IT professionals, for several reasons. First, most company-issued computers and phones come packed with company-specific remote administration software. Usually, that's so when you call IT to fix something, they can connect directly to your computer and take over your screen. Cover blown.
Second, a lot of companies' IT departments have set up your work-owned equipment to prevent workers from installing additional browser plug-ins and software unless it comes from an approved source. Guess what's usually not on the approved list? Yeah.
Finally, even if you managed to get a VPN working on your company's internet, IT can see you're connected to a specific IP address -- a dead giveaway that you're using a VPN. Guess you're going to have to wait until you get home if you want to beat your high score on Robot Unicorn Attack.
Protect you from viruses and tracking
Think of VPNs like cars. Driving around the internet with the best VPN ever made would be like taking the American backroads in a totally unassuming 10-year-old silver Honda Accord, sporting bulletproof black-out windows, plates that automatically match whatever place you're driving through, all while you're secretly packing a 376-cubic-inch, 6.2-liter Supercharged Hemi V-8 engine.
You'd be unsuspicious, camouflaged, anonymized, and fast enough to give yourself a wind-blown facelift. But it's still just a car -- it can't stop you from driving to dangerous places. VPNs likewise protect you during transit from one site to the next, but when you arrive at your destination website, it's up to you to stay safe.
Opened a phishing email? Downloaded a malware-laden attachment? Hit by a pre-installed keylogger? VPNs can't save you there.
Get you online during an internet shutdown
If you find yourself in the midst of a political uprising against an authoritarian regime as it cuts server cables across the country, or if you've just coasted into a hyper-capitalist oligarchy which has endowed privately owned ISPs with godlike powers over your local utility poles -- a VPN isn't going to bring your memes back.
While VPNs can get you on certain blocked sites, and bounce your traffic across national borders into friendlier territory to free you from a lot of government-imposed censorship, they still require a functioning internet connection to get you there. In the case of a total internet shutdown in your area, broadband carriers and mobile data services are blocked whole-hog.
If our VPN-as-a-car analogy still holds, you can think of it like trying to drive a car that no longer has wheels, on a road that no longer exists, on an earth that's totally dark.