Methods for identifying potentially sensitive information and protecting such potentially sensitive information include scanning systems that collect and/or disseminate such information. Without limitation, systems collect and/or disseminate personal identification numbers (e.g., personal identification numbers, tax identification numbers, etc.), such as merchant systems, bank systems, healthcare systems, and the like, that collect, use, or disseminate sensitive information may be scanned to identify sequences of data that are likely to be sensitive, and may take actions to protect such sequences of data. Scanning and protection systems are also disclosed.