Electronic texts, unlike the fixed texts of print data, are subject to inadvertent destruction of both the physical medium on which they exist and the intellectual content of their information. Electronic texts, so easy to edit, manipulate, revise, and improve, have lost their assurance of permanence. There are many ways to destroy electronic data inadvertently. First, the medium is at risk. Then there is the bigger problem of intellectual preservation. Data may be destroyed inadvertently. Many types of accidental changes may occur: a document can be damaged accidentally or as a result of the nature of the electronic resource (for example, a dynamic database, by its nature, is frequently updated, erasing previous data in the updating). Unauthorized tampering with one’s own work, for example to cover one’s tracks or destroy evidence, or with the work of another person, can also destroy electronic data. Lack of metadata and systems documentation, electronic data in forms that cannot be preserved because the software or hardware becomes obsolete or the digital resources have been designed to prevent any copying, and finally a lack of empowering mechanisms to institutions willing and able to be caretakers of our electronic resources all threaten our digital heritage.