In these days of AIDS and promiscuity, the dangers of unplanned X can not be overstated. Such things as making your socket available to any user, or scattering your interactive processes on anothers host, can cause numerous problems, both in terms of viral infection and unplanned children. Although the children can be aborted, many find this course of action much too severe. What can be done to prevent this dreadful situation? Obviously, wearing a chastity belt helps. Placing an inpenetrable barrier between you and your client is always going to be of great assistance, and all the better if they can only make connection by using the correct key. Ensuring that you can only be approached by known hosts is another helpful consideration; indeed, if you make a short list of people who you are willing allow to talk to you, the chances of unplanned X are made much more remote. What about condoms? Does placing a wrapper around all probes give you any more safety. Well, obviously yes. If all active packets are caught by the wrapper, and it is guaranteed that only safe ones can pass through, then you can feel assured of your safety. There is always the risk of the wrapper breaking, though, so you should only use high quality ones, and make sure that there is never an overly large penetration. [originally by me]
(From the "Rest" of RHF)