A network server may discourage inappropriate use. Files may be altered in such a way as to not noticeably affect acceptable, desired file types, but to substantially corrupt undesirable file types. Every file copied to or from a memory of a server may be affected, or the method may be applied only to selected files or types of files. In particular, files that may be corrupted by alternation include executable software files and compressed files, which may be fault intolerant. Fault tolerant files, which may include text and graphics files, may not be noticeably affected. In some cases, copyrighted files, media files, and/or other files are altered to prevent undesirable distribution.