Yep. The solution was to ban cellphones. Go figure.
Operation of cellphones has always been prohibited in flight, along with all other electronic devices that transmit on any radio frequency (intentionally or otherwise).
The FAA makes it the responsibility of the aircraft operator to only allow operation of devices that have been shown to not interfere with aircraft navigation systems. The airlines can't test every one of them, so they prohibit all intentional transmitters, and prohibit unintentional transmitters (i.e. computers) below 10,000 feet.
The FCC has a separate prohibition against operating cell-phones while in flight. This is because it is incompatible with the cell system design, and interferes with communication on the ground. This prohibition has been in effect since cell phone systems have been available to the public.