[CentOS] vfstp and renaiming of files with ftp client

> 
> I have a vsftp server and two users for up and download.
> 
> If user Alice uploads a file, the owner is set to Alice as expected
> "-rw-r--r-- alice ftpuploadgroup"
> 
> Now Bob can login to the same folder and is able to rename the uploaded
> file.
> 
> Bob can also rename an uploaded folder, but can't rename a file in that
> folder ....
> 
> I'm confused, as I don't get why this is possible at all.
> 

What are the permissions and ownership on the directory the uploads go
in? If its group is 'ftpuploadgroup' and has group write permissions
than any member of that group can rename files in that directory. If a
user creates a directory, then that will have rwxr-xr-x permissions so
they won't be able to rename files within that directory.

P.