Comment 22 for bug 48734

@Mark Shuttleworth

I don't know where to start with your flaws, but I'll at least flag a few + relevant points.

1. A majority != all
2. The wiki confirms that this is a security bug
3. People store their mail in the home directory (this is only 1 example). You can then own the user or get the information you need etc. Identity theft is huge and this is only one of the consequences
4. Linux for human beings? We like privacy. Sharing with friends or relatives.. Believe it or not, most friends and relatives like to keep their personal information private, I'm sure you do too
5. You say the word 'assume'. Why would you ever assume trust? Security Engineers are paid to prevent such assumptions
6. Sure you can circumvent via USB boot, but in Ubuntu you can use an encrypted FS or encrypt folders to negate this if you want to
7. Ubuntu is being used in Universities, schools, organisations etc. Wasn't this an objective of Ubuntu - to gain market share/use/awareness in any environment? Are you really ignorant to think that Ubuntu is only being used at home?
8. Real unix/posix operating systems don't make home dirs public. A lot of admins won't even think about checking the perms as a result. We get totally shocked when we first find this out, and obviously a lot have already been bitten.

One only has to look at competitors such as OS X to see that sharing features/frontends have been placed in the Desktop Environment to allow users to easily share files within sub-folders of their home.
You may be suprised, but I have never heard anyone complain that this is hard for an inexperience user to do.