You are thinking only of shell access. There may be other ways that a cracker might use. These do not necessarily involve using a shell account. Crackers use many different ways to deface sites/steal info/do whatever.
Quote:
Originally Posted by reborg
It's like leaving the keys in your car bacuse it is in a locked garage.
To put it in the context of reborg's quote, what you are doing is assuming that the garage is locked, so the car is safe. What happens if the garage is broken into?
And about giving your business partner permissions to change the files, can't you just set access control lists (setfacl/getfacl on Solaris)?