|Image from Quicklabel.|
"Ironically" is the wrong word there; better would be "paradoxically". I've tried to explain this before with reference to the story about Chicago police practice. The original NSA method was a "profiling" approach which tried to limit its data by marking all the "foreign" numbers first, and it dredged up too many dolphins along with its tuna, so to speak. The method they decided to replace it with was a "network" approach, throwing each dolphin back into the water as it came up on the way to the next tuna. It's paradoxical that starting with fewer limitations should get more narrowly tailored results, but it's true.