sshfs mounts with user privileges but for umount I need root. why? how?

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http://askubuntu.com – I'm trying to unmount from nautilus, the directory created by sshfs, but I get this error: Unable to unmount dir umount: /home/user/dir is not in the fstab (and you are not root) I'm not getting why is this happening. How can I unmount sshfs without sudo? Any enlightenment will be appreciated. Thanks in advance, (HowTos)