Facebook is not a privacy company; it's Big Brother on PCP. It does not want to anonymise and protect you; it wants to drain you of your privacy, sucking up every bit of personal data. You should resist the urge to let it, at every turn.
Screenshot: Nosferatu (1922)
There's a new menu item in the Facebook app, first reported by TechCrunch today, labelled "Protect". Clicking it will send you to the App Store and prompt you to download a Virtual Private Network (VPN) service called Onavo. ("Protect" shows up in the iOS app. Gizmodo looked for it on an Android device and didn't see it - though, presumably it is only a matter of time.)
Millions of people use VPNs to enhance their privacy online. But that is not Onavo's function.
VPNs work by forcing your laptop or mobile device to establish a connection to a third-party server before then connecting you to any websites or online services. Using an encrypted tunnel, a VPN can prevent your broadband or wireless provider from keeping track of the websites you visit. What's more, a VPN service can mask your own IP address from those websites, helping you to traverse the net without surrendering locational data. VPNs also help users in authoritarian countries bypass censors by convincing websites their country of origin is, for example, the US or Switzerland, the latter of which has some of the world's strictest privacy laws.
Facebook, however, purchased Onavo from an Israeli firm in 2013 for an entirely different reason, as described in a Wall Street Journal report last winter. The company is actually collecting and analysing the data of Onavo users. Doing so allows Facebook to monitor the online habits of people outside their use of the Facebook app itself. For instance, this gave the company insight into Snapchat's dwindling user base, even before the company announced a period of diminished growth last year.
To put it another way, Onavo is corporate spyware.
If you're someone who can't live without Facebook or simply can't find the courage to delete it, the Onavo appears under the "Explore" list just above the "Settings" menu. I'd recommend you never click it. Facebook is already vacuuming up enough your data without you giving them permission to monitor every website you visit.
If you'd like to use a VPN service, there are literally tens of thousands to choose from. The good ones cost money - usually $6 to $13 a month. It's important to remember, while they mask your activity from your ISP, the VPN company itself may be able to see virtually everything you do online.
For that reason alone, recommending a good VPN service can be tricky. But if you'd like one to check out, try giving Private Internet Access a look. And educate yourself: Read more about how VPNs work at the Electronic Frontier Foundation.