Please, learn laws before post's.
"Personally identifiable information" as used in US privacy law is information that
can be used on its own or with other information to identify,
contact, or locate a single person, or to identify an individual in context.
NIST Special Publication 800-122 defines Personally identifiable information
as "any information about an individual maintained by an agency,
including any information that can be used to distinguish or trace an
individual‘s identity, such as name, social security number, date and place of birth,
mother‘s maiden name, or biometric records; and any other information that is linked or
linkable to an individual, such as medical, educational, financial, and employment
information."
So, for example, a user's IP address as used in a communication exchange
is classed as Personally identifiable information regardless of whether it may or may
not on its own be able to uniquely identify a person.