Missed the point?
Is this about P2P, or competitive practices?
The "big guys" do a little math. We have X likely customers on an exchange. On average, they'll sign-up for Y speed. That exchange can support N bandwidth. That gives us a couple of numbers to fiddle. The highest speed we can advertise, and we'll 'optimize' that by capping monthly transfers so that folks can't/won't max their bandwidth all month. Add calculus, marketing crap, peak times, etc, etc.
What's important is that it's a last-mile bottleneck. It's not a problem on the fiber. Along comes the government who tells the big guys that they have to lease their toys to the competition. Suddenly, the playing field doesn't look as friendly as it used to. Add P2P to this, where folks are using a large chunk of the bandwidth which they've been sold. To keep peak traffic down on the last-mile, throttle it. It's natural to them as they've been doing it for years on their usenet servers (hence, folks paying for third-party). Also start charging $2/gig overage charges.
Smelling blood, the smaller ISP's go after a market of users who don't just send email, surf, and whatnot. That's a competitive edge, albeit slim since, let's face it, most folks don't know or care about the finer points of their connection.
Eventually, the smaller ISP's are creating problems for the last-mile maths. The big guys see an opportunity to remove a competitive edge under the guise of optimizing saturated networks. Done deal.
World of Warcraft updates, experimental releases of DRM-free TV by the CBC, or copyrighted material? Legal file transfers, illegal? I'm not sure that it matters. They aren't enforcing copyrights or anything so noble, they're using it as cover when limiting congestion of outdated last-mile tech, and now to remove a competitive disadvantage. That's it, that's all.
Substitute VPN traffic for P2P. How would that change the reaction to this story?