Error

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