>> I'm always asking *why* (for which reason, or maybe better which
>> purpose) something is done/allowed/not allowed/implemented/...
>> for the question "why is a user allowed to create hard like to
>> files of other users" I haven't found any positive answer yet
>> (please don't tell me "that's UNIX fs semantics" again;)
>> and I found/read no answer so far what we'd break if we would
>> change the behaviour of link(). I still think that it *absolute*
>> no real application will be affected...
>
> Hard links are pretty useful for sharing large files. When I was in
> university, I used to make links to large programs compiled by other
> users - like gdb, irc, etc. In this way it didn't take any additional
> disk space and if the owner deleted the program later, I still had a
> copy.
If the owner deleted the program because they ran out of disk quota,
you made sure that _they_ still owned a copy. You did not have a copy.
I'd say this is a reason to restrict link() to the file owner.