Richard Stallman

A smartphone is a computer - it's not built using a computer - the job it does is the job of being a computer. So, everything we say about computers, that the software you run should be free - you should insist on that - applies to smart phones just the same. And likewise to those tablets.

The idea of free software is that users of computing deserve freedom. They deserve in particular to have control over their computing. And proprietary software does not allow users to have control of their computing.