Short selling is just betting the stock will go down in the most basic sense. This is very important to keep stocks in check.
When short selling was banned, the problem is that stocks will go up if bought, and down if sold, but there was no one pushing the value down to a
more realistic point (as realistic as an emotional irrational market can make it).
Basically there is no reason people shouldn't be able to bet that a stock will be going down. To make short-selling possible, it takes a broker or
someone to lend them the shares too. So there are no shady things happening at all.

