In plain words
It lets a court, an insurer or a regulator rely on evidence by showing it was not changed along the way.
Why it matters to a firm
LeakTrace does not provide a formal chain of custody. Each finding carries the dated command or public source that proves it, so counsel can re-run it and establish custody on their side.
How anyone can check it
For your own records: save the date, the source address and a copy of what you saw, and note who collected it.