when brokers loan out your shares to other parties and they sell into the market it creates a short position as now you got a shareholser with 10000 shares and 10000 of the same shares in the market that don't belonge to them, they are by law require to by back 1n 13 days, it is the same thing when restricted shares are borrowed, get the picture, restricted shares are not suppose to be borrowed or loaned, also many other type accounts like IRA, cash so on, but they do it and get kick backs for it, it is ilegal to do this.