The problem with all phones is that you can't secure them fully. Period. There is no way. The baseband is a mysterious black box chip that has shared access to the system RAM and nothing short of a fully open source implementation of LTE or GSM or whatever will fix that.

The black phone sequesters the baseband and only powers it up when it's being used.

There is no way to achieve that with even the most tin foil totting custom ROM on a standard handset.

I propose to fully apply—for the first time ever—those bright-line rules to mobile broadband.

Such goodwill concessions may seem impressive as Comcast seeks to foster goodwill, but one wonders how Comcast/Time Warner will behave after the merger.