The Immigration and Naturalization Service (INS) has repeatedly sent spies into Arizona churches to collect information about worshippers' efforts to aid Central American political refugees, efforts commonly termed "the sanctuary movement." In both civil and criminal cases, churches and sanctuary workers have argued that the government's sending of informers into religious meetings without prior judicial approval violates worshippers' legitimate expectations of privacy in their places of worship as guaranteed by the fourth amendment. In rejecting this argument, courts have refused to suppress evidence gathered through government-sponsored church infiltration, and have instead held that "as far as the" fourth amendment claims are concerned ... there was no legitimate expectation of privacy."
Mertus, Julie A.
"Ecclesiastical Sanctuary: Worshippers' Legitimate Expectations of Privacy,"
Yale Law & Policy Review: Vol. 5
, Article 13.
Available at: https://digitalcommons.law.yale.edu/ylpr/vol5/iss2/13