The number of people using the Tor anonymizing browser to access Facebook has passed the one million mark this month for the first time, Facebook has announced.

Tor (aka The Onion Router) is a network technology designed to increase the privacy of web users by encrypting and randomly routing Internet connections via a worldwide network of volunteer relays — thereby making it harder for individual web connections to be traced back to a particular user.

Facebook created a dedicated onion address for Tor access back in October 2014, aimed at making it easier for users to connect via Tor, given that the way the network routes traffic can be flagged by site security infrastructure.

Facebook also expanded its Tor support at the start of this year by rolling out support for the Android Orbot proxy, giving Android Facebook users an easier way to use Tor.

The company said today that growth of Tor over the past few years has been “roughly” linear, noting that some 525,000 people access the service via Tor in June 2015 — rising to move than one million this month. (Albeit it’s very much a drop in the ocean of Facebook usage generally, with the company reporting more than 1.59BN users as of January this year.)

“This [Tor] growth is a reflection of the choices that people make to use Facebook over Tor, and the value that it provides them. We hope they will continue to provide feedback and help us keep improving,” Facebook added.

Discussing why users of the social media service, whose business model relies on tracking and profiling users by encouraging them not to be private about their data, might see any point in using Tor’s network to access said service (given that their data is going to be anything but private once they get there), Tor flags up some specific use-cases why the feature might still be useful to people, including location obfuscation.

Its routing system via a network of relays means it disguises the user’s physical location — presumably also cloaking that location data from Facebook. (Albeit, if you fb Messenger your friend about the ‘great holiday you’re having in Chicago’ Facebook is going to be able to figure out where you are anyway…)

Update: Tor has confirmed this supposition, with a spokeswoman for the organization telling TechCrunch: “When using Facebook website over Tor, Tor Browser is in charge of that data, so it is anonymous. Of course, someone may post a status update saying that they are at some restaurant, for instance, and that would de-anonymize them.”

Another reason Tor points to is to ensure a user’s identity doesn’t leak to intermediaries — such as ISPs or “an agency that surveils the Internet”.

“Political activists organize on Facebook: Their public identity is important in their work. So is their safety,” it notes in a statement.

It adds that countries where Internet access (or use of Facebook specifically) is blocked or censored can also be a motivation for people to use Tor as a workaround for that block (i.e. rather than as a specifically pro-privacy service).

“Many people use Tor in countries where the Internet is censored, not in order to be anonymous. Tor allows them to access the uncensored Internet, including reaching Facebook. In Iran, for instance, Facebook is blocked. So people use Tor to get onto the Internet and browse, and from there they can reach Facebook.”

Plus it argues there are security advantages “inherent” in the structure of its network, such as making man-in-the-middle attacks more difficult to carry out.

For its part Facebook does not delve too explicitly into the psychology of its Tor users but just notes that people use Tor for “a variety of reasons related to privacy, security and safety”.

Why does Facebook care about Tor? Providing another route for users who might not otherwise want to or be able to access its service means it potentially gets to keep/gain that small group of people as Facebook users.

But, if you want to be more cynical about it, you could say Facebook is engaging in a little brandwashing of its data-powered business model by cosying up to a well known entity in the privacy/security space — which might result in the perception that it cares about user privacy.

Sure Facebook is happy to protect your data from falling into the hands of companies unattached to its business. But, remember, once you pass through those blue gates it’s a data free-for-all.