Personally identifiable information (PII) is any set of data that has a chance to uniquely identify a person, including name, address, credit card info, social security, etc. It can also include things like birthdate, city, IP address, and so on, depending on how the combination of data works. The general rule of thumb is that you want to aggregate out to the city level at least, or completely anonymize the data. These, I’m supposing, we’re raw records that contained account info.