Hiya guys, kinda new here and I needed some advice.

Someone told me that when a iPhone is serial locked through 'Find my iPhone' (by the previous owner for instance), and you don't have his password to unlock 'Find my iPhone' the phone is useless in every way.
This is a new feature which comes in 7.0.3, and it's fullproof apple says.

what do you guys think?
Is this hack-able with a moderate knowledge of apple-products ?

Regards,
Dab