People are fearful of the BOT NET. If your disc image checks out identical to a retail image, it is the same. Adhering to the EULA/distribution is another story entirely.Poor choice of words there, it can never be legitimate when you download Lion as a torrent.
You can torrent Windows 7. Not that I would when I can directly download it from other sources. Just make sure you pass MD5/SHA-1 checks.