Unexpected change of file owner:group

[J. K. Cliburn]

On 1/20/06, Paul Howarth <paul at city-fan.org> wrote:
> If the directory is group-writable, any member of the group can achieve
> the same result by doing:
>
> $ cp junk junk.new
> $ rm junk
> $ mv junk.new junk

Learn something new every day.  From the chmod manpage:

When the sticky bit is set on a directory, files in that
directory may be unlinked or renamed only by root or
their owner.  Without the sticky bit, anyone able to
write to the directory can delete or rename files.