Anyway, this is why I prefer operating systems whose source code I can view and modify. It is nicer to find bugs by reading the source code instead of logging into your account and finding all your data gone.
Depending on exactly where you draw the line between "code used for user logins" and the rest of the OS, I may have fixed bugs in it, too.
Of course, Microsoft could do most of the same thing if they opened their source. People would read that too. But that's another issue, of course.
In some ways having a late patch from a trusted source is better than a quick one from some random place on the net. The best would be quick, trusted patches, of course. A GPG-style web of trust validation of patches, maybe?
"When guest user logs out, all information and files in the guest account's home folder are deleted."
However, it deletes user's data instead of guest's.
BTW, I would expect it to be in some shell/Apple script anyway, so Open/Closed Source argument doesn't really stand here.
Now, if you changed some piece of the system in order to circumvent FairPlay, or some other DRM component, then you might be running afoul of the DMCA. Not the same thing as copyright violation, however.
(I'm not saying you're incorrect, but being right doesn't make it any cheaper to defend yourself against a dedicated opponent with deep pockets.)
And yet, having the source open did nothing to prevent the Debian SSL-cert bug from happening.
Perhaps it got patched faster because the source was open, but the bug was in there for quite some time before it got caught.
Lots of people have looked at the Windows number generator (or its results) to see if it's wrong. Lots of people have looked at OpenSSL too. But the place they are likely to look is the official releases, not the distro forks.
Being open source allows many small variations to exist. It's not enough to know you're using open source and that a million eyeballs have looked at it. Have the million eyeballs actually looked at the exact source you are running?