The United States v. Jeffrey Grubbs case in 2005 revolved around the legality of anticipatory search warrants, which are issued before the occurrence of a triggering condition that justifies a search. The defendant, Jeffrey Grubbs, was caught in an online sting operation where he ordered child pornography from an undercover postal inspector. A warrant was obtained to search his home once the package was delivered and accepted by him (the triggering condition). However, this information wasn't included on the copy of the warrant given to Grubbs at time of execution but it did include what items were being searched for and seized - violating federal rule requiring full disclosure. He pled guilty initially but appealed later arguing that his rights under Fourth Amendment were violated as he wasn’t informed about true purpose of search when it occurred. The Supreme Court ruled 8-0 against him stating anticipatory warrants aren't unconstitutional per se; they satisfy Fourth Amendment's requirements if there is probable cause to believe evidence will be found after trigger event occurs and if description is sufficiently particularized.

In the dissenting opinion for United States v. Jeffrey Grubbs, Justice David Souter argued that anticipatory search warrants should not be allowed under the Fourth Amendment because they are inherently based on future conditions and therefore lack probable cause at the time of issuance. He contended that such warrants violate a person's right to privacy as they allow law enforcement officers to conduct searches before there is concrete evidence of wrongdoing. Furthermore, he expressed concern about potential abuses by police who could manipulate circumstances to meet warrant conditions or mislead judges into issuing them based on hypothetical situations rather than actual facts. In his view, this case represented an erosion of constitutional protections against unreasonable searches and seizures.