Dynamic: I've recently wondered whether 'fracking causing earthquakes' might even potentially be a good thing. If there is a faultline with pressure building up, surely a series of small movements caused by a bit of man-made lubrication is better than the fault letting to in one big hit.
Fracking is not the lubrication of existing faults for the purpose of releasing seismic pressure. Fracking introduces new geological faults into a complex system. This alters the balance of forces within that system and redistributes forces in unexpected ways.
Ignoring all the other side effects it is exceedingly silly to use this technique near nuclear power stations, fuel storage, dams, etc, etc.
If you or I can explain how inducing a fault in some random place (just because it has the potential for gas recovery) will magically reduce the risk of an earthquake on a major faultline we could earn some serious consulting fees ; ). The reality is that redistribution of energy could just as easily increase the risk on a major fault. Nobody knows.
Evidence is accumulating that fracking is leading to increased seismic activity. Statistically speaking, increased seismic activity is usually a bad thing not a good thing.