Or any other electronic device for that matter.
This has been around the webs for awhile now, I should have posted it sooner.
From speaking with a few professionals their general advice is turn off devices that you don't need. My Turbo Fan goggles are a prime example on the down. Cell phones should be off unless you need them. Any electronic devices you do have on should be at least a foot away from your beacon. Your beacon will still transmit with another electronic device nearby, but the range in which it can be received can be seriously compromised. So just use some common sense.
I've played with several electronic devices and my beacons. All of them caused sort of phantom signal. Hopefully helmet cam guys take note and take some measures to shield their wares. I also hope that beacon manufacturers also take note and do what they can to limit this.
More things to consider and complicate your life in the backcountry is all...