The problem with net neutraility as it comes from the FCC is that it could possibly outlaw the following items:
My ISP setting up mail filters for SPAM. Most of the SPAM I currently get blocked would on the look of it be legal, using the definition of net neutrality most people are using the methods to determine it is trash would not be allowed.
Can schools and businesses still block various web sites; since based on definition they are ISPs? From what is known from the FCC ruling that could be a problem unless the site is dealing with illegal operations.
Or how about something like ISPs blocking common ports used for various attacks but not for other types of traffic? The ports are most likely legal ports and the traffic is probably legal, I presume ICMP is still legal, even if is not something someone should be doing out side of their own network?