Dave, I am not sure, the stock was under $5 since the beginning of the year and the short position doubled since January from 1.7 MM to above 3 MM in June. Probably MM's themselves, since they do not have these limitations. From one of the posts here, I conclude (possibly wrongly) that this stock had a period of "get your certificates" battle cries to prevent shorts attack (helps like wind glasses to a corpse <vbg>), someone mentioned that he earlier moved the stock to a cash account so the shares cannot be lent out (many brokers pay no attention to that small distinction, they have the inventory, they lend it out... many of them have "small prints that let them do it anyhow).