Comment by martin-t
I hate this idea that you always have to be professional when dealing with a corporation and have to follow rules exactly, often rules made up by the corporation. (Laws are just rules too, they are enforced by violence.)
The corporation showed gross incompetence and was punished for it. Sending passwords in plaintext indicates deeper security issues and systemic failures. HN can cry about companies leaking people's personal details but to actually make it affect their bottom line and force them to fix it, it has to affect their bottom line - they must get punished.
Sure, this was not a legal punishment but it was not wrong and it was very minor anyway.
Legality is not morality. Laws are written to protect peace (absence of visible conflict), not to protect justice.