I created a schroot recently (following the directions here), and it conveniently shares my (host) user home directory. That is, /home/username is the same in the chroot as outside the chroot.
Where is this behaviour configured ? How can I prevent this behaviour ?
I'm using Ubuntu desktop 12.04 64-bit, and schroot version info is
$ schroot --version
schroot (Debian sbuild) 1.4.25 (03 Feb 2012)
By default, schroot mount directories according to filesystem table file /etc/schroot/default/fstab. You could comment the line start with /home so that schroot won't bind-mount the home directory.
You could also specify other filesystem table file by editing schroot conf file. For example, if you add setup.fstab=minimal/fstab to the end of /etc/schroot/chrood.d/[your chroot's].conf, schroot would filesystem according to /etc/schroot/minimal/fstab.
Go into the host system (exit the chroot), and run mount. There, you should see where you home directory (and any others) are mounted into the chroot. Navigate to the destination directory and run umount. Something like this should work:
# umount $(mount | grep 'home.*precise' | awk '{print $3}')
where the grep pattern home.*precise is whatever matches the mount points you want to get rid of.