Bricking Unsecure Devices: Good, Evil, Both?

Millions (or tens, hundreds of millions, or billions?) of IoT devices are shipped with default usernames and passwords, which users seldom change, and which malicious hackers can then use in attacks. A hacker by the name of Janit0r released his own virus for these devices, which simply bricks them before they can be used for larger bad deeds. And so the moral question: is this bricking of devices good, evil, or both? Gizmodo's Adam Clark Estes seems to argue for the "good" side, but there are good arguments for each. I'll stay neutral, and make sure to change my default passwords!
[via Ars Technica]