Willful blindness (sometimes called ignorance of law,willful ignorance or contrived ignorance or Nelsonian knowledge) is a term used in law to describe a situation in which a person seeks to avoid civil or criminal liability for a wrongful act by intentionally keeping himself or herself unaware of facts that would render him or her liable. In United States v. Jewell, the court held that proof of willful ignorance satisfied the requirement of knowledge as to criminal possession and importation of drugs.
For example, in a number of cases in the United States of America, persons transporting packages containing illegal drugs have asserted that they never asked what the contents of the packages were and so lacked the requisite intent to break the law.
Such defenses have not succeeded, as courts have been quick to determine that the defendant should have known what was in the package and exercised criminal recklessness by failing to find out. Notably, this rule has only ever been applied to independent couriers, and has never been used to hold larger services (e.g. FedEx, United Parcel Service, or the U.S. Postal Service) liable for the contents of packages they deliver.
A famous example of such a defense being denied occurred in In re Aimster Copyright Litigation, in which the defendants argued that the file-swapping technology was designed in such a way that they had no way of monitoring the content of swapped files. They suggested that their inability to monitor the activities of users meant that they could not be contributing to copyright infringement by the users. The court held that this was willful blindness on the defendant's part and would not constitute a defense to a claim of contributory infringement.
Although the term was originally - and still is - used in legal contexts, the phrase "willful ignorance" has come to mean any situation in which people intentionally send their attention away from an ethical problem that is believed to be important by those using the phrase - either because the problem is too disturbing for people to want it dominating their thoughts, or from the knowledge that solving the problem would require extensive effort. This phenomenon is closely related to the aphorism, "Ignorance is bliss."