As long as my neighbor and I are both paying the same ISP the same amount of money for an internet connection, then we should have the same probability of one of our packets making it through their network. If I'm making an FTP transfer and my neighbor is teleconferencing, it's fine for some of his packets to be delivered more quickly than some of mine, provided that over any given second, we get to transfer roughly the same amount of data. Until our ISP redefines itself as a telecom provider with ancillary FTP capabilities, their QoS strategies shouldn't benefit my neighbor at my expense.

If ISPs are allowed to discriminate significantly based on the protocol, then what's to stop them from inventing a new proprietary video transmission protocol and prioritizing that over any protocol used by YouTube, effectively reimplementing discrimination on the source or destination of traffic (which is the most obvious justification for net neutrality)?