http://arstechnica.com/security/2015/01/bug-in-ultra-secure-...
Also, for those claiming that it is still uses insecure baseband chips and firmwares, the phone comes with Silent Circle suite apps which allows you to make end-to-end encrypted calls and messages, so even if you have a flawed baseband chip, it was built so you could have secure calls and messages through wifi, 3g or 4g, without worrying about the security vulnerabilities of those chips.
-secure transmission of data between two points
-PGP
-secure web browsing
-staying anonymous to uncle sam
-staying anonymous on the web
I don't trust it. If anything the Blackphone is just one huge target / honeypot for the government.
With the proper hardware and software modifications, you can come close (if not better) to what the blackphone has to offer in an off the shelf rooted Android.
Most of the security apps will require that the other person has the same apps. I find that rarely will people use those apps.
I would choose a better experience on an iPhone 6 and just accept nothing is secure.