An interesting way to hide paper trails as far as money goes when working under a pen name would be to set up a paypal account with a prepaid credit card, and set up another paypal under your name and your normal bank account to do transfers. There will be a few small fees for transfers and maintainance of course but if you're expecting a fairly decent income the fees are easy to deal with, and it leaves a confounding paper trail for anyone beyond sanctioned agencies who bothers to pry into your business. Here in the U.S. other than the IRS, government officials, or credit bureaus, anybody who digs that deeply into a private citizens banking records is likely to get thrown in jail for looking into bank records that have nothing to do with them (the data is relatively private from citizen to citizen) so it's not a common investigation tactic used by those not affiliated with such an agency (likely an obsessed fan would not even go as far as hacking bank records unless they are stupid) government agencies would probably care less about you using a pen name as long as you filed the proper paperwork and kept up on the income taxes for anything earned.
