Oh yes, it can absolutely be done. I have not looked to see if PHGI is listed on the Berlin Exchange, but I'm sure JB has requested a delisting, if so.
Otherwise, you are correct about the CDN Brokers. But there are US based ones who do it as well.
All we, as shareholders can do, is place our shares in the "cash" portion of our accounts. Shares cannot be borrowed for shorting from a cash account, or an IRA (or other Ret. account) only from a margin account.