Ankheroo
A broker can lend clients shares when
1. they are held in a margin a/c
2. a cash a/c customer gives written permission
Fully paid shares are held in segregation & can't be used by the broker.
An efficiently run brokerage lends out as many margin clients shares as possible as he receives cash to put to work & pay down other loans he may have against bonds or whatever.
In my opinion you are "tilting at windmills". Remember for every short sale there is an offsetting long purchase. At some time in the future the short has to buy back. There is a huge risk for a short when an offer may be made at any time!! It's not that frequently you get a "short squeeze" & you certainly won't get it with ARU. I would like to see lots of short sales because it will provide underlying share price strength & could provoke a buying stampede when there is a rumor of a takeover.
Regards
Joltin