The last time I used a lot of data I used 2GB in a day while I was watching Xfinity On demand. I think I watched 2-3 movies while I was at work.
I don't think that is excessive... but if I was to do that everyday and use 50GB+ of data a month, I would fully expect my service to be cut off. Right now we are lucky that we have unlimited data without Sprint planning to end it any time soon. If people start abusing it though that will change.
"With great power comes great responsibility" and right now I consider unlimited mobile data great power!
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery? Forbid it, Almighty God! I know not what course others may take; but as for me, give me liberty or give me death!"
-Patrick Henry, March 23, 1775