This would be an ineffective way to accomplish that. They'd first have to make a list of all the phones in the target area, and then they'd have to send the lock commands to them, one by one.

Furthermore, even if they went through all that trouble, it only would work on smartphones. The bill does not apply to feature phones, other non-smartphone phones, laptops, or tablets. The bill defines a "smartphone" as a cellular radio telephone or other mobile voice communications handset that includes ALL of the following features:

• Utilizes a mobile operating system.

• Possess the capability to utilize mobile software applications, access and browse the Internet, utilize text messaging, utilize digital voice service, and send and receive email.

• Has wireless network connectivity.

• Is capable of operating on a long-term evolution network or successor wireless data network communications standards.

The bill explicitly says that "smartphone" does not "include a radio cellular telephone commonly referred to as a 'feature' or 'messaging' telephone, a laptop, a tablet device, or a device that only has electronic reading capability".

(Added in edit) Also, while the bill requires that smartphones be equipped with this and that it be on by default, the bill does NOT require that it stay on. Apple's iOS 7 kill switch lets the user turn it off, and I believe that is what Samsung plans to do. People going to protests or other events where they think authorities may try to disrupt communications can simply turn off the kill switch before arriving at the protest.

It would be much more effective to silence a particular area by doing something at the cell tower layer or higher.

> I have a hard time believing that stolen phones are a big enough social problem to warrant a mandate of this scope

Stolen phones account for half of all robberies in San Francisco. In New York, they are 20% and rapidly rising. It's the #1 property crime nationwide, accounting for 1/3 of all property crime. In half of the San Francisco incidents the victims are punched, kicked, or physically intimidated, and in a quarter of them they are threatened with a gun or knife.

That sure seems like a big enough problem to me to try to do something about. We also know that kill switches are effective. In the first five months after Apple put in a kill switch, iPhone thefts dropped 38% in San Francisco, 24% in London, and 19% in New York. We know this wasn't just due to a general lowing of crime rates, because in the same time period overall New York theft went down 10%, and Samsung phone theft went up 40%.

Phone[] phones = GetPhonesByGeo(radius=50, lat=102.23412323, lon=-129.4342424);

foreach(Phone p in phones) { p.sendmessage("Lock"); }

func GetPhonesByGeo(){ // your tax dollars at work }

There is no requirement that an API be provided to law enforcement. That "sendmessage" method could come down to someone on the law enforcement side getting on the phone with Apple or Google or Microsoft or a service provider and telling them the numbers to kill.

This is assuming that Apple or Google or whoever even can flip the kill switch without the assistance of the phone's authorized user. They could easily design the kill switch system so that the person flipping the switch has to know the authorized user's password [1]. There is nothing in the bill that I see that says they have to design the kill mechanism to allow law enforcement or the manufacturer or the carrier to be able to use it.

[1] For instance, the phone could ask for your iCloud or Google account information when you set up the kill switch for the first time, and then it could store on the phone a hash of the concatenation of your password and the phone serial number. The kill switch mechanism could require that the kill command include that hash, thus proving to the phone that the sender had access to your password.

You don't know what you are talking about.

EDIT: yes, please, go ahead and explain how you're going to get phone's location geographically. Hint: not everybody has data turned on always. Or GPS.

This is not a Batman movie you know

Its not perfect, but they can get your position by just measuring your signal strength to the multiple towers and triangulate the rest.

No, this is not a batman movie. For more, check out http://worldwide.espacenet.com/publicationDetails/biblio?CC=...

Do you have a source to back up the stats in this section?

> This would be an ineffective way to accomplish that. They'd first have to make a list of all the phones in the target area, and then they'd have to send the lock commands to them, one by one.

This doesn't seem to hard, if you have all of the phones connecting to one or two towers (Or you set up your own "Stingray" tower).

Now the standard line before a protest speech will be, "Please turn your phones to silent, and turn off the kill switch please..."

http://blogs.wsj.com/metropolis/2014/03/03/new-york-bill-wou...

http://www.csmonitor.com/USA/USA-Update/2014/0515/Minnesota-...

http://phonetheftfacts.com/facts-and-information/recent-news...

http://blogs.findlaw.com/technologist/2014/06/iphone-thefts-...

http://www.nydailynews.com/new-york/kill-switch-lowers-iphon...

So this bill is probably just what it seems - a way to curb cellphone pilferage.

The way it works is that important people not "subs" have phones with two sims so that the emergency services etc can talk with out.

(Sure, you can probably come up with some hypothetical scheme involving public key crypto, but we know they're not doing that, and if they did most users wouldn't be able to figure out how to kill their own phones either).

So, yeah, the technology is clearly going to be able to be used so the government (or really, the cell provider or anyone that can convince/force the provider company to do something) can shut down any cell phone, or even all cell phones in a given specified area (that is, currently in contact with specified access points). Of course, they could just shut down the towers too, maybe more likely to be used against selected numbers or lists of numbers.

Anyhow, that was my first thought too. On seeing the headline, I even first thought that was the _point_ of the legislation, you know for 'national security'.

But maybe there could be a succesful campaign against this on 'national security' grounds, it makes our communications network less secure, chinese army hackers are gonna get into it and kill peoples phones! Meh, probably would not work.

(Sure, you can probably come up with some hypothetical scheme involving public key crypto, but we know they're not doing that, and if they did most users wouldn't be able to figure out how to kill their own phones either).

You don't need any crypto. The user sets a killswitch password in her phone, then the command must provide the same password. If the user hasn't setup any password, the command works without one.

  No, it's nothing like a kill-switch.

I seem to recall the BART authority doing something similar with their infrastructure during recent protests - it was quite effective.

That said, the bill requires that the kill-switch have an option to be disabled, so there's no reason you couldn't just disable it before hand.

They can do that already just by shutting off the cell tower or blocking specific users from it.