I have a friend who is worried about privacy issues and was telling me that he does not want to discuss some subjects anywhere in the vicinity of a cell phone because, he thinks, it’s possible that cell phones, even when they’re not activated, might be picking up sounds around them and transmitting them somewhere where people might be listening.
To me this sounds like paranoid fantasy. However, I’d like to get some input on this from people who actually know something about the subject.
Thus:
Can a cell phone which is not activated, or even turned off, be transmitting sound elsewhere?
Is there any way that computer filtering can be used to sort through very large numbers of conversations to pick out key words?
(on this latter, I am really not inclined to believe it - it’s hard enough to get speech recognition software to recognize ambiguous words even when it’s been trained to one particular voice)
Highly doubtful. For one thing, its fairly easy to measure whether a cell phone is sending out any communications and if anybody ever discovered it doing such a thing, there would be massive consumer backlash. Also, sending requires power, it would be impossible for cell phones to maintain their current battery life if they were constantly sending out streams of data.
Well, I agree that it is a bit paranoid, but I have had the following happen to me: I was playing around with my phone, and I set up a voice activated phone number to a friend. I could place the call by clicking my bluetooth headset button and then speaking her name. It turns out that the button was getting pressed while the headset was in my pocket, and because her number was the only one I had set up to call by voice activation, my phone was automatically dialing it even though I hadn’t said a thing (unless my pants somehow said her name…). Anyway, she got a lot of random calls from me where she could just hear me in the background. I finally figure out how to turn the whole thing off, but it was annoying for a while, and she could have definitely been eavesdropping if she really wanted to.
Nah, I don’t see it used to eavedrop on the owner. However, your friend has reason to be paranoid about something else.
Your cell phone network knows where you are; it has to, to find you when someone wants to make a call to you, it has to know where to go to connect to you (it can’t go “searching”; that would be too cumbersome). This is true even if the phone is not being used (but it does have to be on). Periodically, the cell phone will send out a signal to the local network that identifies the phone to the nearest cell phone tower. Some will tell you that you really only have to be concerned about GPS equipped cell phones, but that’s not so. Multiple cell towers can “triangulate” on a cell phone “ping” (the periodic signal the cell phone sends out) to get a fairly accurate idea of where you are in the cell.
In cell phones are software controlled radios. They can be programmed to do most anything.
Battery life is one of the most watched specs of a cell phone. They get 300 hour standby time by turning every thing off but a low power timer that wakes the phone up every few seconds to listen to see if there is a call coming into it. If the phones are one listening for conversations and then transmitting the conversations that drains the battery really quick. It seems unlikely that a person’s phone would do such a thing without their knowledge.