[Excerpt] This Article explores an underappreciated and promising NLRA protection of collective activity. It elaborates the NLRA’s role as a defense in state defamation cases. Specifically, this Article explains how the “NLRA defamation defense” frees defendants from some forms of defamation liability when the allegedly defamatory statements are made during labor disputes. The defense has no effect on defamation liability in what this Article refers to as “more egregious” state defamation law cases. However, the defense forecloses liability in “less egregious” state defamation law cases. It makes it harder for defamation plaintiffs to win their cases because it requires them to satisfy a heightened standard of proof. In this way, the NLRA defamation defense limits the ability of defamation lawsuits to serve as “a powerful weapon for shutting up those with whom [one] disagree[s]” in the labor context. In other words, it reduces the likelihood that state defamation law will chill the free flow of speech and collective activity with the threat of monetary awards, sometimes in the millions of dollars. While all parties to labor disputes who face defamation claims can take advantage of the NLRA defamation defense, this Article focuses on the use of the defense by employees and both traditional and non-traditional worker organizations to highlight an important aspect of the NLRA’s protection of collective activity.