I'm sure the first thing that comes to mind is personal safety. In the course of investigating UFOs, we as Field Investigators come into contact with the public on a regular basis. As an ethical, conscientious investigator, we are all to go into each situation with an open mind, and no preconceptions about the witness. This isn't always easy to do, especially when a witness is less than honest.
It would be foolish for me to imply that every witness has a sterling character. That just isn't the case. Unfortunately the subject of UFOs has been so infiltrated by everything from agents of disinformation, to reports from people suffering from paranoid schizophrenia or other delusions, that we have to be able to sift through them and distinguish which cases are credible. And of course, the ones that aren't are the cases that you want to be especially careful with your personal information on.