if your using an online tax service from home...do some research on the company, if you pick one, make sure it's a secure site....If you go to a tax pro...again, check with the BBB if you have a question, or go to one that's been recommended....There are the big 3 companies...but that doesn't guarantee you that your privacy. It's the businesses responsibility to protect your info.
So look for the following if you go to some place...
*Tax files are not out in the public view.
*Computers are not just were anyone can view the screens.
*Files are in locking cabinets, or locking room in back area.
*Only the managers and Tax Prep employees are at the desks, other then the client they are working with.
Those are the biggest things of concern and most places know this, but if you see any of these issues...RUN!