Ignorance of the Enforceability of a Contract is No Excuse

In Commil USA, LLC v. Cisco Systems, Inc., 2015 WL 2456617, *9 (U.S. March 31, 2015), a patent infringement action, the United States Supreme Court discussed the rule that ignorance of the law is no defense. In doing so, it noted that per the Restatement (Second) of Torts, Section 766, while the  invalidity of a contract is a defense to a claim of tortious interference, the belief that the contract is invalid is not. Even if you interfered while innocently believing that the contract was not enforceable, you can still be held liable for tortious interference.  So if you're going to assume the contract is not enforceable, you better be right or you better be willing to accept the consequences.