Does fracking cause earthquakes?

An article published today in the Winston-Salem Journal states that fracking has been linked to increased earthquakes in Walnut Cove, North Carolina citing recent research linking the drilling method to increased earthquakes in Oklahoma.

Back in January of this year, TV and radio talk show host Glenn Beck interviewed Miami University of Ohio professor Michael Brudzinski whose research has been cited by opponents of fracking stating the procedure does cause earthquakes. Brudzinski says there is a lot more to his work than what is being quoted. Basically, fracking opponents and the media are leaving out an important point he made in his study.