Including a counter in each UDP packet does not make ECB mode equivalent to CTR mode.
Let's assume the counter is at the start of the packet. An AES block is 16 bytes, so the counter ensures the first 16 bytes of ciphertext are unique across packets. But any patterns in the remainder of the packet are preserved, within and across packets.
"the right of people to express their opinions publicly without governmental interference, subject to the laws against libel, incitement to violence or rebellion, etc."
You've created a false dichotomy between an absolute right to free speech and absolute disregard for free speech.
There's a third possibility, which is to believe that freedom of speech is an important right, but not an absolute right that trumps all others.
One version of this belief says that freedom of speech is useful to society because it allows dissenting views to be resolved through debate rather than violent conflict. It would be reasonable to argue that speech that incites or promotes violent conflict doesn't qualify for protection on these grounds.
Another version of this belief says that freedom of speech is just, because society should only intrude on an individual's freedom (e.g. by preventing them from speaking) when the exercise of that freedom threatens another individual's freedom. Again, speech that incites or promotes intruding on other people's freedom, to an extent greater than the intrusion caused by preventing the speech, could reasonably be excluded from protection on these grounds.
It's obvious how either of these beliefs about free speech would be compatible with censoring speech that promotes violence or the overthrow of democracy, while at the same time being compatible with objecting to the censorship of other speech.
But here's where it gets interesting for me. From the point of view of the Chinese Communist Party, the demonstrators in Hong Kong are threatening the stability of a society that within living memory has seen periods of instability that killed millions. From their point of view, the demonstrators are acting violently and putting millions of lives at risk.
I wouldn't personally argue that speaking out in favour of the demonstrators is promoting violence. But the line is less clear than I'd like.
Let's assume the counter is at the start of the packet. An AES block is 16 bytes, so the counter ensures the first 16 bytes of ciphertext are unique across packets. But any patterns in the remainder of the packet are preserved, within and across packets.