Comment 20 for bug 10550

One thing worth noting is that in the default setup for Ubuntu, file permissions
won't prevent the user from reading data off the disc, since the first user is
added to the "cdrom" group, who has read/write permissions to the block device.
 So file permissions won't provide any real security in this case.

Secondly, if the user has a Windows box available, it will give them full access
to the data. It'd be interesting to know what other operating systems do with
UDF file permissions (eg. MacOS X, BSD, etc).