With some increasing frequency, courts must review law enforcement agencies’ use of new technology that enhances legitimate investigations if used properly but also threatens personal privacy if misused. Courts review the use of these tools most often under the principles of the Fourth Amendment and its prohibition against unreasonable search and seizure. Although the text of the Fourth Amendment does not indicate that a warrant is required to make a search or seizure reasonable, the Supreme Court has ruled that there is a presumption that a warrant is required for a search to be reasonable, unless some exception to this rule exists.