It's not a permissions issue. For some very silly reasons the /sbin and /usr/sbin directory are not on the default user path. A simple solution is (as root) just type "ln -s /sbin/lsusb /bin/lsusb"
It is not the path issuse. See below:
$ lsusb
cannot open /proc/bus/usb/001/001, Permission denied (13)
I run the command by other users and got the permission denied error.