I have to say that I only found this site today an

I have to say that I only found this site today and didn't do research on where they get their numbers from.
If its derived from FINRA #'s then these are probably long sells from MM's who are designated as shorts, but aren't real shorts.

Example: Investor A is long 100 shares and wants to sell. They enter the order through their broker that is routed to a market maker. That market maker will go out and sell the stock into the market before they have bought the stock from you/your broker to close out their account. They do not take possession first as there is no guarantee they can sell the order into the market. By this Notice, the actual sale INTO the market is a short sale because the market maker sold the stock into the market BEFORE they had purchased the stock from you. It is a technicality since they know there position will be closed out minutes later when they go in and buy your shares. To avoid doubling up on trade volume and distorting the picture, only the sale into the market (consolidated tape) is recorded and not the second leg which was the sale transaction between seller and market maker. So, this is why the short sale volume is high but also why the FTD’s and bi-Monthly short interest reports are not showing any indications of this volume. The short isn’t really a short it is the execution of a long sale by a market maker.