Silent Circle's Blackphone is a niche device that puts privacy and security front and center. It's a no-compromise solution for anyone that absolutely needs a powerful but secure device, and it has slowly gained popularity for that exact reason.
The bad news about any smartphone getting more popular is that famous devices tend to get knockoff and counterfeit devices trying to cash in on their brand name and features. Obviously, clone devices aren't good for any manufacturer, but they're especially damaging to a company like Silent Circle who bases their entire sales pitch on security. A counterfeit device is probably not secure, and they can't have knockoff products tarnishing that perception.
So, instead of leaving these hacked together Blackphones out in the wild, Silent Circle has taken matters into their own hands and soft bricked any unauthorized devices running their custom Silent OS. They originally sent out a warning to these devices in the middle of January, but the latest OS update (version 3.0.8) will absolutely stop any unauthorized devices from working.
Silent Circle has official channels to buy their devices in all parts of the world, and anything outside of those channels can't be guaranteed to still be safe and secure. There could be all sorts of hidden malware or tracking services loaded on the devices, which completely defeats the point of why you'd buy a Blackphone.
Hopefully this bricking situation doesn't too leave too many people out of a phone, but it's always important to try and buy your devices through official channels, not resellers on eBay.
source: Ars Technica
Overpriced and underpowered. I can secure my OnePlus 3 just as easily.