[folmar]

I'm afraid you only take into account private use.

On-endpoint filtering is not enough on a large scale. In a network with expected high level of security I don't trust the endpoint and censoring them is a feature, there is no moral or legal expectation of privacy, but data integrity would be nice.

[josephcsible]

If you own all of the endpoints, then it is indeed morally okay for you to do network-level filtering. The problem is that if we design network protocols so it's possible for you to do that, then it will also be possible for people to do network-level filtering that affects endpoints they don't own.