In message <199601042211.OAA04284@gabriella.resort.com>, John M Vinopal writes:
> for anonymous incoming, the uid will be identical and thus sticky
> bits are no help.  
> 
> a umask which makes incoming files unwritable would be the answer.
> but how to apply a umask to the ftp anon process?
> 

Actually, a umask wouldn't help either - UNIX allows you to delete unwriteable
files as long as the directory is writeable.  Presumably, you could hack the
daemon to disallow deleting or overwriting existing files.