Yesterday and Orem, Utah man was arrested for stealing names, addresses, and account numbers off of the checks that he processed at his job as a clerk at a convinience store and then selling them to would-be identity thieves. This case is not about digital identity, but its a good example of why the principle of least privilege is important. In general, whether online of off, we're asked to give up more identifying information than is strictly necessary. This clerk had access to more information than he needed, strickly speaking, to do his job. This is true when you use your drivers license to prove your age as well. The clerk can see you address and phone number, but they're irrelvant to the transaction at hand. One more reason to not use checks.