[colorado tanker]

There might be something to this, although the culprit is probably the disposal wells, not the fracking.

A deep disposal well drilled on the Rocky Mountain Arsenal in the 1960's caused minor quakes here until it was shut down.

[Buckeye McFrog]

There have been proposals to pump water deep into the San Andreas Fault. The object being to relieve the stress along it’s length in a series of small quakes, and thus avoid “the big one”.

Perhaps the frackers are doing them a favor.