Pivoting is the core investigative skill of using one artifact as a doorway to the next. A username leads to accounts; accounts leak emails; emails reveal breaches and further accounts; those accounts expose real names; names connect to public records. Fluent pivoting is the difference between having one data point and having a corroborated portrait.
Every pivot should be corroborated and documented, and each conclusion labelled by confidence — a shared registration detail is a fact, while "therefore the same person" is an assessment.