"It is clear that many faculty occasionally ignore incidents of suspected academic dishonesty in their courses. In the surveys discussed here, 41% of faculty acknowledge having done so and the primary reason they offer is the burden of proof required to prove a student has cheated. They frequently complain of cases where ‘obviously guilty’ students have been found not responsible. ... If they have not had such an experience personally, they know a colleague who has. Unfortunately, such inaction in the face of cheating leads to even higher levels of cheating as students quickly become aware of which faculty are not likely to pursue cases of suspected cheating and their courses become targets for cheaters."

McCabe, D.L. 2005. Cheating among college and university students: A North American perspective. International Journal for Educational Integrity 1:1-11.