Delete default folders: Documents, Public, etc -- permanently?

I do not use the folders ~/{Downloads, Documents, Public} and so I remove them. But some Mac OS X process keeps recreating them. How can I disable the creation of these folders permanently? What process(es) are creating them? Note: I do download files, e.g. from Safari, but they then go to a different directory. Safari allows this to be customized, so why can't the default directory be erased? Note: I have run a crontab to delete these folders on a routine basis, however this is not a satisfactory solution especially since it needs to be run by root or an administrator.