What you're describing is called 'fractional reserve lending'. Its something all banks do since its an easy cash-flow when you lend out assets that are not yours, rather than simply have them sit in a vault. They get angry when you want your stuff back, because it exposes the sham, and makes them vulnerable to eat the risk and losses from the lack of the asset that they had come to rely on to keep a flow of dollars coming in.

So that explains all the delay and runarounds and belligerence on behalf of the bank. Think of them as bums trying to sneak out of the casino without paying the house the $ they lost, and you wont be far wrong.

I dont know why a broker would give a shit about what you do with your $ however, as long as you keep using their services. And it takes a dumbfuck broker to get angry at the guy you want to keep around... since thats a pretty sure way to get even less business and commissions/brokerages on trades.