How to make my `/usr` folder secure?
It seems the permissions on /usr are incorrect, which in the past has been attributed to installing MacPorts. You can repair the permissions on /usr by running:

sudo chown root:wheel /usr
sudo chmod 0755 /usr


Since MacPorts installs to /opt/local, this shouldn't affect MacPorts, but as I don't use MacPorts I can't say for certain.