Someone can correct me if I'm wrong, but I don't believe that Comcast "blocking" access to HBO Go has anything to do with net neutrality. In that case Comcast is saying that the HBO cable subscription they sell doesn't include HBO Go access. This is possible because of the requirement to "authenticate" your HBO Go access through your cable/satellite provider.

So that has more to do with television than internet regulation IMO.

But it does, on PC. Just not PS4 and PS3.

I can login to HBO GO with my Comcast account on PC just fine, always have been able to.

It's still an agreement between Comcast and HBO based on TV subscriptions - it's not like Comcast is null routing the packets that would allow "authentication". Luckily, the market (i.e. HBO, in the face of consumer demand and competition) has already worked around these stifling agreements by providing the unbundled HBO Now. Which Comcast can't block, DNSSEC misconfiguration notwithstanding.

Comcast isn't blocking anything there, they are failing to take positive steps that enable their TV customers to use a service that is dependent on verification that they are Comcast's TV customers with an HBO subscription

Even though it is a service provided over the internet, what Comcast is doing (or, more precisely, delaying or failing to do) is in their role as a Cable TV service provider, not as a broadband ISP.

Now, once HBOs streaming service that is independent of a TV contract is available, if Comcast were blocking that (whether generally or on a device-specific basis), these rules would apply to that blocking.

That was due to a DNSSEC misconfiguration, it had nothing to do with net neutrality. The misconfiguration affected android devices as well.

You seem to be mistaking the newly launched HBO Now for the existing HBO Go service. Comcast continues to block the latter on certain devices, even for paying customers.

I wasn't aware that was the issue. I was under the impression it was a business decision by Comcast.