Keep in mind that you also might want to disable bluetooth services as they are not needed, and or disable the bluetooth stack so that if a bluetooth usb is plugged into the port it won't work also.
just took me a bit to realize I was having a moment of brain dead, THANK YOU ALL! - THX 😉
BTW:
if you want to perform a serious Squid + Squid Guard installation.
I have an acquaintance here on the forum and I can bring you together with him...☺