An intelligence time machine is a concept first articulated to me by network security expert Eric Rescorla. The idea is that there may be some point in the future when an intelligence analyst will wish he had collected some piece of intelligence in the past. But he can’t know today exactly what intelligence he may want in the future, so any selective collection method always leaves open the possibility that he may fail to collect what he will need. If instead he collects everything, he has effectively built himself a sort of time machine: in the future, he can go back and reprocess the data to find the intelligence he didn’t know he would need at the time it was collected.