I worked in a comptuer store over the holidays and the GM was always going on about “shrinkage” (theft) and a number of the clerks were claiming that the sensors in and out of the store, were too sensitive and the cell phones people used were setting them off.
Well I know it can’t be totally true that cell phones set them off, 'cause I’ve seen people talking on cell phones and walk straight through them without setting anything off.
So IF cell phones can set them off it must be only at a certain time. I googled this and I came across one site where a lady said, he cell phone would set it off but only if the battery on the cell phone was really low.
I guess that MIGHT be the case as the power may be fluxuating.
In the computer store I worked at all the security was RF, not of the magnetic variety.
So what do you think? Can cell phones set of the security alarms? And if so under what conditions.
It’s plausible.
IIRC, almost all “sensormatic” type systems are RF based, and cell phones are pocket-sized RF factories. If the security system’s not shielded properly, or if a phone’s not quite right and putting out spurious signals, (dropped it a few times?) a phone could easily offer signals to confuse the system.
The battery isn’t going to make a difference.
What will make a difference is whether the cell phone is transmitting at the time. Cell phones transmit on occasion even when you aren’t using them. Periodically, the cell tower sends out a signal that is basically “yo, are you still there?” and the cell phone response with a “yup, I’m here” message. The cell phone also transmits when you get an incoming text or picture message. There’s some back and forth signaling since the cell phone has to acknowledge that it got the message.
Most theft deterrent systems these days are designed to reject cell phone signals, but you could always have a poorly designed system or an old outdated system, or maybe even a system that wasn’t quite installed properly (see gotpasswords comment about shielding, for example).
Theft deterrent systems will also sometimes false trigger on certain things, like the RF tag based security badges that we use where I work.
Not a store, and not RF, and not cell phones - my library uses a magnetic stripe and an antenna to check. Although the antenna is supposed to be sending on a certain frequency only, we get alarms from books from other libraries, too, and from laptops when the WLAN card is active searching.
I also once touched off an alarm at a store when I had my laptop with active WLAN card; the next time with WLAN inactive, it didn’t go off.
We had a regular customer who would always set the sensors off when coming in, who would quickly state that it was her phone, so that when she went out and also set them off, the door greeters would just let her go. Loss-prevention got suspicious after a while and tailed her, and caught her shoplifting. It turned out that she had one of our active Sensormatic tags attached to her phone, so that she could demonstrate that her phone was responsible.
I discovered once that Sensormatic tags deactivated for the local Best Buy were activated for the local Wal-Mart, and the same tag if then deactivated at the Wal-Mart became active for Best Buy again. That stopped when we upgraded systems, but it was annoying.