Important Notes
For two weeks after you delete your account, Facebook retains your data in case you wish to reverse your decision. If you don’t log in to Facebook for two weeks, your account will be permanently deleted.
Immediately after deleting your account, clear the cache of the browser(s) you use to log in to Facebook. Doing this is another way to make sure that you don’t accidentally log in to your Facebook account or use it in the two weeks after deleting it.
Facebook provides the following disclaimer about deleting your account: "Copies of some material (photos, notes, etc.) may remain in our servers for technical reasons, but this material is disassociated from any personal identifiers and completely inaccessible to other people using Facebook." In other words, your data could remain on Facebook’s servers for a while, but it is no longer identifiable as your data, nor is anyone able to search for it. Eventually, your old data will be overwritten and forever deleted.
If you accidentally use your Facebook account within two weeks after deleting it, you’ll need to initiate the deletion process again.