Informed Bystanders' Duty to Warn

Should bystanders with credible knowledge about prospective harm owe a duty of care to future victims? This urgent question comes up in various contexts, from former employers who withhold information about a serial harasser to data brokers who are silent about stalkers that track personal information. Under established common law, the “No Duty to Act” (“no-duty”) rule generally does not require bystanders to warn strangers. Carving out an exception to this rule decades ago, Tarasoff v. Regents of the University of California imposed a duty on a mental health professional to warn a prospective victim about the risk posed by a dangerous patient.

Yet existing tort scholarship and doctrine undertheorize the grounds for such a duty to warn, and courts struggle to apply the duty in appropriate cases beyond the medical context. Offering a fresh take on Tarasoff, this Article makes the case for a duty to warn owed by those I define as “informed bystanders.” I first identify four criteria that courts tend to implicitly consider in deciding whether to recognize the duty: Expertise; Certainty; Cost; and Position of Power or Special Capacity. I then question the theoretical necessity of expertise as one of these criteria. Next, I advance two arguments to support informed bystanders’ duty to warn.

The first argument—couched both in the common law’s self-interested individualism and in feminist legal theory—posits that the no-duty rule’s default should be flipped to generally recognize a duty to warn. According to the second, narrower argument, the no-duty rule need not be changed. Instead, existing exceptions to the rule should apply to the special relationship between informed bystanders and future wrongdoers or victims. Finally, I address potential pushbacks, contemplate models for implementing the duty, and flag key cross-private law implications.

The Article thus begins a crucial conversation on tort law’s nasty habit: allowing bystanders to withhold information that could prevent harm to others.