When you see the number of shorts against a stock on a website, it only represents the legal shorted shares.
Usually, when there are 100 legal shorted shares, there is ALOT more naked shorting going on behind the scenes. So there might be 1,000 illegal naked shorted shares, which will never be reported on.
It's almost impossible to find out the number of true shorts against a stock. The only two methods I know of are:
1) The company can run a NOBO list, and an OBO list, add the shares together, and see how shares total are owned in their stock. Shareholders cannot do this. Companies usually only get the NOBO list, because the OBO list is more expensive.
2) Buy all the shares in the float. If there is still trading, it's shorted!