Both lp, the System V printing system, and lpr, the Berkeley Software Distribution (BSD) printing system, provide remote printing options. These allow a computer to print to a printer that is physically connected to a different computer. Obviously, in a local area network this is highly desirable; you shouldn't need as many printers as you have machines. However, the remote printing options are both insecure and inefficient as ways to transfer data across the Internet. There is no reason to allow them. If you have a need to print at a site across the Internet, or to allow another site to use your printers, it's possible to set up special mail aliases that print the mail on receipt. This is the method many companies use even across in-house wide-area networks because it's considerably more reliable.