freebsd jails # rm -rf mail
rm: mail/mail/usr/lib/librt.so.1: Operation not permitted
rm: mail/mail/usr/lib: Directory not empty
rm: mail/mail/usr/lib32/libcrypt.so.5: Operation not permitted
rm: mail/mail/usr/lib32/libc.so.7: Operation not permitted
rm: mail/mail/usr/lib32/librt.so.1: Operation not permitted
rm: mail/mail/usr/lib32/libthr.so.3: Operation not permitted
rm: mail/mail/usr/lib32: Directory not empty
rm: mail/mail/usr/bin/yppasswd: Operation not permitted
rm: mail/mail/usr/bin/chsh: Operation not permitted
rm: mail/mail/usr/bin/opieinfo: Operation not permitted
rm: mail/mail/usr/bin/ypchfn: Operation not permitted
rm: mail/mail/usr/bin/ypchsh: Operation not permitted
rm: mail/mail/usr/bin/chfn: Operation not permitted
rm: mail/mail/usr/bin/login: Operation not permitted
rm: mail/mail/usr/bin/crontab: Operation not permitted
rm: mail/mail/usr/bin/passwd: Operation not permitted
rm: mail/mail/usr/bin/rsh: Operation not permitted
rm: mail/mail/usr/bin/opiepasswd: Operation not permitted
rm: mail/mail/usr/bin/chpass: Operation not permitted
rm: mail/mail/usr/bin/su: Operation not permitted
rm: mail/mail/usr/bin/rlogin: Operation not permitted
rm: mail/mail/usr/bin/ypchpass: Operation not permitted
rm: mail/mail/usr/bin: Directory not empty
rm: mail/mail/usr: Directory not empty
rm: mail/mail/bin/rcp: Operation not permitted
rm: mail/mail/bin: Directory not empty
rm: mail/mail/lib/libcrypt.so.5: Operation not permitted
rm: mail/mail/lib/libthr.so.3: Operation not permitted
rm: mail/mail/lib/libc.so.7: Operation not permitted
rm: mail/mail/lib: Directory not empty
rm: mail/mail/libexec/ld-elf32.so.1: Operation not permitted
rm: mail/mail/libexec/ld-elf.so.1: Operation not permitted
rm: mail/mail/libexec: Directory not empty
rm: mail/mail/var/empty: Operation not permitted
rm: mail/mail/var: Directory not empty
rm: mail/mail/sbin/init: Operation not permitted
rm: mail/mail/sbin: Directory not empty
rm: mail/mail: Directory not empty
rm: mail: Directory not empty