How many times have you covered this topic Tor. You have gone into depth about this at least 5 of 6 times over the last 5 or 6 years. You should save the long version explaintion, and just post it every time.
From poeple I talked to you can short anything if you know the right broker. Hell its almost the same thing as booking a football bet with your bookey. Thats not leagal is it.