Who determines if a security is short-able how many shares?

[vissertrades]

This short crap is bugging me.

Market for loaning shares:

www.tradeaqs.com/

Is there going to be an end to the short availability or is it market driven by potential for $? Seems counterproductive to investing in my mind - just a gambling tool to make money!

[vissertrades]

Can't short stock below $5? I'm sure dirty short bastards have found away around that too!