Whatever happened to the right to free speech? There are of course restrictions to free speech, such as you cannot yell fire in a crowded building unless there really is a fire, but this is not one of those scenarios. The behavior of Verizon and the other ISPs are grossly offensive!
Don't forget about defamation. Sure, you can spread lies in order to do me harm. But I can sue you for the damage done by those lies. Why would you think that lies that damage a reputation are substantially different from vandalism that damages a building?
Not that I think Verizon actually has a strong case for defamation. Netflix should have little difficulty arguing that they had good reason to believe that their claims are true. I don't think this is going to end well for Verizon.