The author does not seem to understand that ISPs sell 'best-efforts' grade services. What this essentially boils down to is that contention ratios are a fact of life. They rely upon the fact that not everyone is online at the same time, and not everyone is trying to back up the Internet at the same time. By and large this concept works. What ISPs are saying is that the 'hogs' will use far more (at least an order of magnitude more) than your average punter. This places the ISP in an unenviable situation - either they increase the cost of the service for everyone, or they put measures in place to make sure that everyone gets a fair share of the pie.
Yup in NZ ISPs who wholesale DSL off telecom pay for xx kbps of bandwidth per user, 24, 32 or 40 i think it is kbps for UBS/UBA, and 180 or 240 i think for EUBA.
What this means is that if your ISP had say 1000 users, you'd only be able to transfer at the rate you're purchasing per user * # of users at any given time. Thankfully not everyone uses the net at the same time which is why even with a allocation say 32kbps per user you can get full line speeds, but I wouldn't be suprised if a number of NZ ISPs are hitting their handover link allocation as a result of their customer demographics at certain times of the day (I'm just guessing this last part and don't know of any who actually are)