The United States Supreme Court has held that a search warrant based on information from an anonymous informant can withstand a constitutional challenge when viewed by a "totality of the circumstances" approach.
Illinois v. Gates, 103 S. Ct. 2317 (1983).
Megan E. Harmon,
Constitutional Law - Fourth Amendment - Search and Seizure - Probable Cause,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol22/iss4/13