The fleet of mobile devices (Nokia and Windows Mobile) all use WiFi to connect to the internet. There wasn't a good tethering option. The fleet are all in downtown Mountain View (a place flooded with varying WiFi signals. This problem is compounded by having dozens to hundreds of devices in close proximity to each other. We found that the devices would not hold a reliable persistent connection which would cause intermittent Talos test failures. Each of these failures could potentially waste a person's time to go deal with it which in turn wastes money. Hence they came up with the Faraday cage.

Please note this is just the story as I understand it from taking a tour of the room. I might have missed something important or subtle there. :)

What exactly are they testing here?

Probably builds of Fennec on Nokia Maemo devices.

I don't think anyone else is even trying to ship Gecko on cell phones.

Windows Mobile is another target: https://wiki.mozilla.org/Mobile/Build

I'm glad this wasn't another PR stunt about mobile phone viruses -- we don't live in that particular William Gibson novel. Pics here: http://radian.org/notebook/van-helsingfors

I do wonder what the chain of hardware issues is that's causing their interference problem. Perhaps the phones all use SoC designs where the CPU, modems, and possibly RAM are all on one die -- would that allow extreme WiFi / cellular noise to flip bits?

Another possibility: they are testing software, so want to keep the CPU free. But phones in a noisy environment are continually trying and failing to connect, wasting resources. Not sure why one would affect the other so much though, so this is a sketchy guess.

Or: Shoe racks become a technological breakthrough in Mozilla's Faraday Cage.