The point is you have a path to trace if needed. Say some criminal has done that, they've established some kind of contact with the "cash strapped person" to do so - either electronically or in person. Electronic traces are pretty feasible for major nation states to uncover since they're ingesting packet traffic metadata from the whole internet traffic of countries. In-person traces can often be covered by surveillance camera records etc etc. Once there is a point of entry, there is usually a path for entities with governmental powers to investigate.