Sorry, it is not fun for your friend unless he had an absolute trust in you, and knew you'd help him remove every backdoor/keylogger/etc.
He may have spent a lot of time securing his machine, time he'd rather have invested in different things.
Seriously, don't do that. Just tell him about the obvious weakness - send a proof of concept if needed.
But a friend is more precious that some cracker creds.
The fact that this crosses peoples minds really concerns me. Have we so degraded our respect for things that belong to other people that we're willing to do this as part of a publicity stunt?
It's part of growing up.
Saying that, the author needs to give better context.
Is an author always required to include a disclaimer? Stupid is as stupid does.
Im gonna guess unsalted md5?
Agreed with the first comment - no fun at all for your friend indeed. The links are good at the end, I've read about a few of those tools even being relatively non-technical. I think more people should have a basic understanding of how to maintain security, but, this doesn't strike me as the best way to teach folks.