Implied consent is consent which is not expressly granted by a person, but rather implicitly granted by a person's actions and the facts and circumstances of a particular situation (or in some cases, by a person's silence or inaction). For example, if a person is unconscious as a result of injuries sustained during a traffic collision, medical treatment may be provided to that person, despite the unconscious person being unable to expressly grant consent for that treatment. The term is most commonly encountered in the context of United States drunk driving laws. Driving while intoxicated All U.S. states have driver licensing laws which state that a licensed driver has given their implied consent to a certified breathalyzer or by a blood sample by their choice, or similar manner of determining blood alcohol concentration. Implied consent laws may result in punishment for those who refuse to cooperate with blood alcohol testing after an arrest for suspected impaired driving, including civil consequences such as a driver's license suspension. In 2016, the Supreme Court of the United States in Birchfield v. North Dakota held that both breath tests and blood tests constitute a search under the Fourth Amendment, concluding that requiring breath tests is constitutional without a search warrant, however, requiring more intrusive blood tests involving piercing the skin is not, as the goal of traffic safety can be obtained by less invasive means. Specifically addressing implied consent laws, the court in the Birchfield opinion stated that while their "prior opinions have referred approvingly to the general concept of implied-consent laws" that "there must be a limit to the consequences to which motorists may be deemed to have consented by virtue of a decision to drive on public roads" and "that motorists could be deemed to have consented to only those conditions that are 'reasonable' in that they have a 'nexus' to the privilege of driving". In 2016, People v. Arredondo, the California Courts of appeals debated whether authorities could seize an unwarranted blood sample from an unconscious person suspected of driving under the influence without offending the Fourth Amendment's guarantee against unreasonable searches or seizures. The court ruled that the defendant "consented to such a search in advance solely by operation of the statute in California, which declares that anyone who drives a vehicle in this state is "deemed to have given his or her consent" to blood alcohol testing under specified