What is the burden of a plaintiff who argues that a warrant was issued on less than probable cause?

A plaintiff who argues that a warrant was issued on less than probable cause faces a heavy burden. "[W]here [the] circumstances are detailed, where reason for crediting the source of the information is given, and when a magistrate has found probable cause, the courts should not invalidate the warrant by interpreting the affidavit in a hypertechnical, rather than a commonsense, manner.... [T]he resolution of doubtful or marginal cases in this area should be largely determined by the preference to be accorded to warrants." United States v. Ventresca, 380 U.S. 102, 109, 85 S.Ct. 741, 746, 13 L.Ed.2d 684 (1965). In particular, where the officer requesting the search warrant relies on an informant, the magistrate's role is to examine the totality of the circumstances and to