In a campaign supposedly intended to force Walmart to grant its workers better pay and working conditions and reinstate workers allegedly fired for union activities, defendant union began sending demonstrators into Walmart stores for “flash mob” non-violent demonstrations. After unsuccessfully filing charges with the NLRB, Walmart sued in state court for trespass, obtaining an injunction against in-store demonstrations. Held, the NLRA does not preempt state trespass law in this instance. While the NLRA is presumed to preempt state law with respect to activities arguably protected or prohibited under the NLRA, that presumption can be overcome when the conduct at issue is peripheral to the NLRA’s concerns or touches upon interests so deeply rooted in local feeling and responsibility that it cannot be assumed Congress meant to override them. With respect to conduct, such as that involved in this case, which is only arguably prohibited by the NLRA, not arguably protected by it, state law claims may proceed if the controversy presented to the state court is different from that which the NLRB would decided if presented with an unfair labor practice charge arising from the same conduct. Here, state court trespass proceedings are concerned only with where conduct occurs and whether the property owner has consented to it. By contrast, any unfair labor practice charge would be concerned with whether the demonstrations coerced workers in their choice of voting for or against a union in a unionization election. Since the inquiries were different, the NLRA did not preempt the state law trespass claim.