Comment by __b__

The parent stated "Data generated on my phone belongs to me."

I interpreted this as "Data generated by me on my phone belongs to me."

The user could agree to license her rights to the data, e.g. via terms and conditions. But it's still her data. That's why the agreement is necessary.

None of this has anything to do with "reverse engineering".

The scenario I am thinking of is a user looking at her data being sent from her hardware over an internet connection that she is paying for.