Still, the whole purpose of a password is to remain secret. He's certainly doing these users a disservice by releasing this list regardless of the hypothetical likelihood of the data already being available. Basically the arguments for doing this all seem to boil down to "they should already know their passwords are compromised" which nobody can guarantee is the case.

I agree that having a crappy password puts you at risk, but what about the people who genuinely tried to use some common sense but are on this list anyway? Is it their fault for not religiously keeping up with the latest indexed password lists?