Another possibility is that a malicious person in the computing community may try to destroy others' programs or to gain unauthorized entry. If there is no protection on memory, then there is no hope of stopping such people.

Closely related to the issue of protection is that of relocation. Programs are usually written so that they start at location 0 in memory but in reality only one program can do this at any given moment. In fact, the operating system often occupies low memory, words having low numbered addresses such as 0, 1, 2, ... Thus, some way has to exist for either rewriting programs or transparently moving them from one location to another.