Just how different is this from a 911 call center's "reverse 911" capability?
Reverse 911 isn't a mass surveillance technology. To localise the alert Text or Presidential cut in messaging service requires the authority to know where you are located continuously.
The main issue I have is the mass surveillance aspect of the new government mandated chip. The chip will have to interact with the phone OS so that it can over ride it much like non mask able interrupt feature. It will have the ability to end a conversation that you may be having (you could for instance be indicating to the police authorities where exactly a terrorist bomb might be located or saying your final goodbyes to loved ones) to prioritise the government message. i.e. it would be a network government mandated QoS system to ensure governmental communication priorities. i.e. a localised kill switch. It should also be noted that Interweb communications are now used more than voice data.
The other specifications for the built in chip could be even more interesting, such as key word searching from voice recognition (gets around very specific NSA data transmission bandwidth infrastructure issues), voice buffer recording so that conversations can be recording i.e. the last 24 to 72 hrs, much like a black box aviation recorder, location tracking (useful to location stamp the voice recordings), covert recording of audio and video and Internet tracking and recording, data mining and voice and internet kill switching.
There is no data protection legislation for personal information in the USA.