I found in privacy policy of one particular exchange that it transfers data about me to credit organizations. Actually the same is true for banks.
In what cases do they do this thing? If I make big enough trade volume at exchange, say $50,000 for year, is this information transferred as well? I suppose it happens only if you do margin trading or something... don't know much about it, except that you take loans from brokers...

Yeah I realize $50k is not big for you