Comment Re:Seatback charging on airplanes (Score 1) 93
Most likely reason for this might be that, there might be a loose connection and the phone detected the connection as a data connection instead of pure power connection rather than anything sneaky happening.
This is done b shorting out the D+, D- pins through a ~200Ohm resistor which indicates to the phone that it can draw more than 500mA from the source (500mA is the maximum current a standard USB port can provide on a computer).
Reference:
A good source:
http://www.maxim-ic.com/app-notes/index.mvp/id/4803#3
Especially the last paragraph in the section header.
http://en.wikipedia.org/wiki/MicroUSB#Power