While evidence obtained during searches by private individuals is admissible, the application of the Burdeau rule is subject to several limitations. Even if evidence is found during a private search, this does not permit police to make a warrantless entry to retrieve the evidence if it is in an area where there is a reasonable expectation of privacy. If police explicitly request an informant or private citizen to conduct a search, the search is no longer private as the searcher becomes an agent of the Government. Searches also are not considered private if they are mandatory and pursuant to regulation rather than private reasons, such as searches of carry-on baggage at airports. If officers neither request nor participate in an unlawful search, they still are required to stop the search. Failure to do so makes such a search subject to the fourth amendment and the exclusionary rule. However, in lawful private searches, the passive presence of police does not transform the search into an action by a Government agent. Court decisions concerning privacy interests remaining in evidence obtained through private searches have reached mixed conclusions, but in general, police should avoid exceeding the scope of the initial private search. 36 footnotes.