What role did Google’s Play Store play in Viber’s Saudi Arabian blockage?

Last week it emerged that the Skype(S msft) and WhatsApp rival Viber had found its service blocked in Saudi Arabia because it doesn’t meet local “regulatory requirements and laws.” At the time of writing, there are reports that Viber is back up and running in the kingdom, but Viber CEO Talmon Marco isn’t sure. “Some users say that it is working, others say it is not,” he told me. The team won’t be able to know for certain for a few hours.

So what led to the blockage in the first place? Censorship by an authoritarian state? Probably — based on a 2010 incident in which BlackBerry(s bbry) caved in to Saudi demands, allowing the authorities to bypass the encryption of BlackBerry services in order to spy on their citizens, Marco reckons there’s “a certain weight” to the idea that the Saudis want to do the same with Viber. But no-one has approached the company to request such access, he said.

“It could be that it’s a commercial interest in the disguise of a national security interest,” he added. “I don’t know.”

What does seem to be clear is that the blocking happened at the ISP or carrier level, rather than in one national fell swoop. And, according to Marco, there’s an interesting wrinkle to the way the blocking was carried out. “They’re blocking us in two ways,” he said. “One is obvious: identify that the traffic is Viber and block it. The other one, which is more surprising, is how they are specifically preventing Android users from downloading our app.

“They’re taking advantage of a vulnerability in Google(s goog) Play. When you download an app in any other store, the app is downloaded over HTTPS. With Google Play this is different – all apps are downloaded in clear text. This is a vulnerability [Google] could patch within minutes.”

I’ve asked Google for comment. It seems there’s a lot to be cleared up here, both on a technical level and in terms of motivation – were Saudi operators displaying coordinated aggression against an over-the-top rival to their own communications services, or was there a more sinister censorship push from the government? Time will tell.