I’m surprised Oklahoma isn’t doing the same since they have been having a bunch of EQs since 2008. It continues to this day.
http://earthquake.usgs.gov/earthquakes/map/
the exact cause of the low level rumblings is not known, but one thing is true, North Dakota has a LOT of fracking...and almost zero earthquakes, too
so, just having fracking, does not mean earthquakes
they do look for fault lines before they drill, these guys live in the area they drill in, they dont want to poison their own food and water, either