If you want to keep networks private, you can now use locked travelnets. Locked travelnets can be used by their owner, people with a keychain who have been granted access (see locks mod), and finally people who entered the right password (provided the owner did set one).
Note: If you add a locked travelnet to an existing network that contains normal stations, people can still travel from the normal station to your locked travelnets. But they can't travel from the locked travelnet to other destinations on the network unless they are authorized.
