Story time, I'm gonna post this while I wait at Tim Horton's for my friend to get off work.
When I first bought my first ever smartphone, bell gave me a NON DATA contract. They told me if I used data they would charge me out the butt. This was very true, I got a $500 phone bill once for watching a few YouTube videos.
Anyway, fast forward to last summer. I bought an unlocked Galaxy Nexus and swapped my SIM card. Great phone, great new experience, until i realized i had been using 4G for a week straight. When the phone bill arrived I cowered in fear - only to find it costing $40.
... Fast forward to now. Ive torrented movies, watched HD stuff all the time, and they never charge me. I tether my new Nexus 7 all the time. They either don't know or just don't care.
tl;dr I'm not paying for 4G/3G usage on my phone and I use it all the time with no consequences.
Discuss.