What Is Willful Blindness?

In the law, willful blindness is a deliberate attempt to remain ignorant about facts which might make someone liable. In many regions of the world, it is not accepted as a defense and can in fact be prosecuted. This is also sometimes known as contrived ignorance or willful ignorance.

A common example of willful blindness can be seen in cases in which people who act as carriers for drug smugglers argue that they did not know what was in the packages they were carrying. In these cases, the carrier deliberately makes sure that she or he is never explicitly told that a package contains drugs. In this situation, the carrier is exercising willful blindness by trying to remain ignorant, at least officially, of the fact that an illegal act is being committed.

One reason willful blindness is not generally considered a good defense to illegal activity is that, in most cases, it would have been reasonable to suspect that illegal activity was occurring. In cases where there was a high probability that actions might be suspect and people fail to ask for information, they can still be held liable under the argument that they should have been aware, or that they had reasonable belief that something was illegal, even if they did not necessarily know what.

Source: http://www.wisegeek.com/what-is-willful-blindness.htm