Professor Radsan argues that some instances of physical surveillance can be intense enough to be considered a search under the Fourth Amendment.  As such, Radsan argues that the law of surveillance should change to better balance individual freedom against the government’s duty to protect against attacks.  In particular, Radsan compares the utility of the two tests announced by Justice Stewart and Justice Harlan in Katz v. United States and concludes that Justice Stewart’s totality-of-the-circumstances test is better suited to distinguish between different levels of physical surveillance.