Well sort of, it is possible to sell unlimited bandwidth if you have enough capacity at a fixed rate to sustain it. In Australia you can get unlimited bandwidth but you'll be capped at a set speed. 1Mbit of bandwidth in Australia realistically costs ~200-300/month. It's unlimited but it isn't oversold (cause you can't do more than 1Mbit).
Stu
so it's limited to 1Mbit?
'unlimited' is an industry-wide lie.
Well, yeah... Actually in Aus it's called 'unmetered' because when some providers tried to say 'unlimited' the consumer protections regulator slammed them. I tend to agree 'unlimited' is an industry lie, usually it's unlimited*
* As long as you don't break out usage forecasts.

Stu