What sort of data mining was used to find out about his purchases?
Kalifornia DOJ agents are known to hang around the parking lots of local gun stores and gun shows, here in Reno, recording license plate numbers. One of them has been trespassed off of at least one gun store that I am aware of. That said this guy most likely shot his mouth off to the wrong person. The new thing is to rat your relatives or friends out. I am curious how he bought the guns in Nevada.