How does using what you contracted to get amount to "abusive behaviour"? There are other ways to prevent ping flooding. Perhaps the same way we limit things like free speech by; saying it's only free so long as you don't harm others.
If they advertise "10mbits unlimited" then they have to deliver "10 mbits unlimited". If they want to prevent overuse, then why don't they just say "10mbits, 1tb quota" or something similar. That's how it is here in Australia. I have a 200gb plan and anything I use above that is shaped to 256k. My use fits well within that and if I need more I can up to a 500gb or 1tb plan. No uncertain "acceptable use" clauses. I can transfer 200gb, and as long as I'm not doing anything illegal like attempting to hack into a government database or peddling child porn, I don't need to worry about getting reprimanding calls from my ISP or LEO.
The net neutrality debate is NOT about preventing abuse, as many naive people would like to believe. It is about ensuring that home users don't develop services that compete with commercial ones.
For example, Google doesn't want anyone starting up community-run OwnCloud instances reducing the attractiveness of Google's services now do they? How hard would it be to run a server to sync your contacts, files, calendar and other PIM data either yourself or with a group of friends? We're pretty much there with open source software like OwnCloud and Zimbra. THIS is what Google and other service providers don't want. They are protecting their ability to monetise you and charge you for the basic services that could be done privately, securely and effectively yourself.