KYC information are unfortunately a requirement for these services. If they don't require KYC, they might get shut down by the government; especially if the business is running in the US.
we take that as a given, but bitstamp is known for horribly invasive KYC that is difficult to comply with. they don't simply require an ID and proof residence like most exchanges. occupation, net worth, annual income,
source of funds, etc including
proof. good luck
proving your mining, trading, or any other crypto-sourced income.
even when people have complied with their KYC re fiat income, bitstamp has tied funds up for months and closed their accounts. they also have a history of imposing unfair fees/exchange rates when returning the customer's money.
i would
not recommend bitstamp to anyone.