Through a program called WebEOC, TSA collects information about incidents at airport checkpoints. It is used to identify data points of significant security value.
The ability to identify patterns and "connect the dots" on certain incidents cannot be underestimated. In the post 9/11 world such analysis is key to protecting the American public. It was also a recommendation of the 9/11 Commission.
Identity matters. Positively identifying passengers is an important tool in a multi-layered approach to security and one that TSA has bolstered significantly during the past 18 months.