10. The system of claim 9 , the computing device further configured to: re-index, in response to a change to the file and based on the file being designated for backup, the changed file.
9. A system comprising: a computing device that includes at least one processor, memory, and at least one program module according to which the computing device is configured to: maintain an index that comprises tokens that correspond to words that are included in a file in a storage including words added to the file and words deleted from the file, wherein the maintained index of tokens correspond to the added words and the deleted words; determine whether the file is located in a protected namespace; receive an event indicative of deletion of the file; when the file is located in the protected namespace: copy the file to backup storage; update the index with new tokens corresponding to added words included in the file; maintain tokens for added words and deleted words in the index subsequent to the file in the protected namespace being deleted from the storage, wherein the maintained tokens correspond to the added and deleted words; and delete the file from the storage.