<Dd> (I) t is not conclusive to observe, as the plurality does, that "(a) ny member of the public could legally have been flying over Riley's property in a helicopter at the altitude of 400 feet and could have observed Riley's greenhouse ." Nor is it conclusive that police helicopters may often fly at 400 feet . If the public rarely, if ever, travels overhead at such altitudes, the observation cannot be said to be from a vantage point generally used by the public and Riley cannot be said to have "knowingly expose (d)" his greenhouse to public view . </Dd> <P> Nevertheless, O'Connor concurred with the plurality opinion because she thought the defendant still needed to show that public use of the relevant airspace was uncommon . The Justice closed by saying flights less than 400 feet (120 m) in altitude "may be sufficiently rare that police surveillance from such altitudes would violate reasonable expectations of privacy ." </P> <P> Justice Brennan, joined by Marshall and Stevens, strongly believed that the plurality had misstated the issue, agreeing with O'Connor that the frequency of public air travel was a necessary consideration, and that the key issue in the case was whether ordinary citizens were normally in the air above the defendant's home: </P> <Dl> <Dd> The police officer positioned 400 feet above Riley's backyard was not, however, standing on a public road . The vantage point he enjoyed was not one any citizen could readily share . His ability to see over Riley's fence depended on his use of a very expensive and sophisticated piece of machinery to which few ordinary citizens have access . </Dd> </Dl>

In riley v. california (2014) the supreme court quizlet