i hold my shares in Ameritrade and lets say someone calls ameritrade to short SPNG. Ameritrade then borrows my shares and sells them to complete this short.. every short (sell) has a buyer on the other end.. if the buyer holds his shares in another house like E-Trade will etrade note that these shares have been sold in a short and disallow them from being borrowed again in another short transaction?
hmmm.... also seems that the SEC knows that ALL fail info does NOT appear on REGSHO:
11. Can I obtain fails information? Currently, threshold lists include the name and ticker symbol of securities that meet the threshold level on a particular settlement date. Some investors have requested that the SROs provide more detailed information for each threshold security, including the total number of fails, the total short interest position, the name of the broker-dealer firm responsible for the fails, and the names of the customers of responsible brokers and dealers responsible for the short sales. The fails statistics of individual firms and customers is proprietary information and may reflect firms' trading strategies. The release of this information could be used to engage in unlawful upward manipulation of the price of the securities in order to "squeeze" the firms improperly.