Cell phone jammers...do they really exist?

I’ve read stories of places like Apple that have cell phone jammers in their premises to keep secrets from leaking out (i.e. cell phone camera pics). Are they real? And, do any of you have them where you work?

yes they do exist…

I was readying a recent national geographic about the Iraq war; about the IED disposal guys. They have these jammers called Warlocks that block the cell phone signals that “terrorists” use to detonate bombs.

anyway, it sounds like they work pretty well and I am sure that that tech is coming to/in the corporate market stateside…

yeah, you can buy them in Isreal,
They are marketed to restaurants and theatres, to block cell phone noize pollution.

I’m not surprised they exist, what I really meant do companies use them at workplaces to keep employees from leaking out secrets? Are there any places where you work where these jammers are being used?