I keep reading not to leave BTC on the exchanges, but it takes so much more work to know how to remove the BTC. Ledgers are out of stock until September, etc. etc.
Once someone loses BTC by leaving it on the exchange then they will definitely learn how to properly do it because they lost money.
They'll go thru the exact same amount of work but they'll be poorer while they're doing it.
RE: BITCOIN | 66,000BTC Moved Within Hours Of BTC-e Operators Arrest