One reason it may bother them is if they are actively lending out shares to be borrowed for shorting. This is why I have been trying to get peeps to put their shares on GTC sell orders! My understanding is that if your account is a cash account, then it does not matter because the shares cannot be borrowed. BUT if you own shares in a margin account and you don't have them set for sale using a GTC order, then they can be made available by the broker for shorts to borrow them. You could have a broker that has lent, or may want to lend, out your shares to be borrowed by a short! This is just what I have come to believe from my years of trading and reading about this practice. I will see if I can dig up links.
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