The new FAA guidelines regarding PEDs are an improvement, but unfortunately they are being misreported by the press.

The actual guideline is that PEDs can be left on in good visibility conditions, but pilots can ask people to shut them off in fly-by-instrument situations when electromagnetic interference could be catastrophic. Under the circumstances thats a good balance as reported incidents of interference are rare, but unfortunately most of the news media reports aren't mentioning that detail, and are instead spewing technically inaccurate nonsense about airplanes being impervious to interference, thus setting the stage for inevitable arguments from passengers in the future when people are asked to turn PEDs off on a rainy day.

Here is what the FAA's FAQ about the new reg says. (You can read the whole FAQ by clicking through the link below.)

At certain times — for example, a landing in reduced visibility — the Captain may tell passengers to turn off their devices to make absolutely sure they don't interfere with onboard communications and navigation equipment.

A few relevant facts:

1. All electronic devices emit electromagnetic fields. All. Even if they don't have a transmitter or the transmitter is off or the thing is in "airplane mode." There are other emissions at other frequencies. Digital electronics emit powerfully at their clock cycle frequency, for example.

2. Interference between a device and an airplane is some combination of the device malfunctioning and the airplane shielding being damaged. Both of these things can occur as devices and airplanes age, but the perfect combination is rare, which means that most of the time most devices don't interfere. This is why the plane didn't crash that time you left your device on accidentally.

3. It does not follow from that fact that your device didn't cause that plane to crash that time you accidentally left it on that no device could ever cause any plane to crash under any circumstances.