Scientists from the University of Western Ontario used satellite radar data to determine that an 2011 earthquake in Lorca Spain appears to have been triggered by human activity. It looks like the earthquake would have eventually happened anyway, but human activities like fracking may be enough to trigger such events to happen sooner rather than later.
Obviously, earthquakes cannot always be avoided. One scientist in the study said that even rain can trigger enough imbalance to start the process
The study warns that, in certain earthquake prone areas, many human activities that change the water table may be enough to trigger slippage of a tectonic plate. Such activities such as fracking, borehole drilling, and quarrying need to be done considering the larger consequences.