Or, more seriously, if it is salt that was extracted from the sea, there shouldn't be much harm in putting it back. The fresh water that was extracted will end up back in the sea also, so overall there should be no increase in salinity (except locally where the salt is dumped).
http://www.warponline.org/uploads/contents/103-content-9.-En...
It's also the case that most of the desalination methods produce concentrated brine instead of dry, clean salt (so extracting the salt would require further energy), but not needing that much of it is the bigger reason.
Seems like there ought to be some kind of further usage of it.. industrial or otherwise.
Given typical water usage, you quickly have salt for an awful lot of people (salt for hundreds of people per person consuming the water).
I guess other users would be welcome, even if they just take it for free that probably saves the desal plant on disposal costs.