I recently sold shares of AT&T and spinoff WBD. I have no idea when I aquired shares, share price, what the purchase price was, or how I aquired them. How would the IRS know when, how, or where? I might have owned shares before divestiture, or after the split. Computershare can only provide records from when I started with them in a direct re-investment plan. What will the IRS tell me?