Computer Science An Overview _J. Glenn Brookshear _11th Edition
In a data structure based on a pointer system, the deletion of an item usually
consists of changing a pointer rather than erasing memory cells. Thus when
an entry in a linked list is deleted, the deleted entry actually remains in
memory until its memory space is required by other data. What ethical and
security issues result from this persistence of deleted data?
changing a pointer rather than erasing memory cells
原文：http://www.cnblogs.com/yuanjiangw/p/6067921.html
