I've used that last trick a couple of times when stuff was over-optimistically promised "today, end of business", sending out random bytes renamed to .zip and having the real file ready next morning when people complained about not being able to open yesterday's zipfile.
I've used that last trick a couple of times when stuff was over-optimistically promised "today, end of business", sending out random bytes renamed to .zip and having the real file ready next morning when people complained about not being able to open yesterday's zipfile.