So it appears that people do care about their privacy after all. What with the never-ending revelations of US government spying and various other security concerns over the last few months, people could be forgiven for becoming a bit complacent over it all, but apparently that’s not the case. The evidence? The number of people using Tor clients – which serve to bounce your IP address all over the web, making netizens virtually untraceable – has apparently doubled in the last ten days.

The rapid growth in Tor client users since August 19 was first noted by Roger Dingledine, current director and one of the original masterminds of the Tor project, on the Tor-Talk mailing list:

“And it’s not just a fluke in the metrics data — it appears that there really are twice as many Tor clients running as before.”

Oddly, Dingledine admitted that he had no idea what the reason for the sudden increase was:

“Anybody know details? It’s easy to speculate (Pirate Browser publicity gone overboard? People finally reading about the NSA thing? Botnet?), but some good solid facts would sure be useful.”

There’s been a good deal of speculation of course, but so far no one has been able to offer a good explanation as to why that is.

One poster suggested that the increase might have something to do with the recent expansion of web censorship launched by the Russian government – instructions on how to get around these controls feature prominently within the Tor Browser. Alternatively, some suggested that it could just be due to the Pirate Bay, which has been heavily marketing its PirateBrowser in the last few weeks.

Other theories range from an increase in Iranian and Syrian – Iran often cranks up its own web restrictions at ‘sensitive’ times, while Syria is likely to have done something similar with the military conflict in that country intensifying over the last few days. Then again, it could just be something more innocuous like the inclusion of a Tor client in a new but popular app – or it could be something more malevolent, such as a botnet has started using it.

We also can’t discount the latest, ongoing revelations of the NSA’s spying, while the closures of services like Groklaw, Lavabit and Silent Circle may have also enticed people to step up their own privacy efforts.

If anything, it’s likely that the spike in Tor traffic is a combination of all of the above.

Stats show that the biggest traffic increases can be seen in Brazil, France, Germany, Italy, Russia, Spain, the UK, USA and the Ukraine, and that curiously, the sudden increase happened almost simultaneously in all of those countries.

So what did happen on August 19 that sparked a sudden rush to embrace Tor among thousands of far flung netizens around the world? Was it my own post explaining why your email will never, ever be secure (doubtful I know)? Or was it just the botnet after all? With any luck, the people at the Tor Project will come up with the answers soon.