A district court has overturned previous rulings limiting police powers.
A New York judge has issued a written defence of a decision to give the FBI access to a Gmail account in a money laundering case.
On June 11 the court granted permission to agents to rifle through emails sent, received and drafted from the account, as well as the address book and "a variety of other information associated".
Similar applications previously brought before courts in Kansas and Washington DC were refused, with the latter case ruling that the seizure of an email account without "probable cause" was unconstitutional.
Magistrate judge Gabriel Gorenstein wrote: "This court respectfully disagrees with the D.C. opinion on this point because we believe it too narrowly construes the fourth amendment’s particularity requirement and is contrary to copious precedent."
The fourth amendment of the US constitution protects citizens from "unreasonable searches and seizures", and prohibits the issuing of warrants that do not "particularly" describe the place to be searched and items to be seized.
However, Gorenstein noted that many cases concerning the search of a documents "sanctions some perusal" of irrelevant papers to determine whether they are pertinent to the charges.
He added that it was "well established" for a search warrant to permit off-site access to electronic files even if not all information seized is relevant, because of practical constraints.
"We perceive no constitutionally significant difference between the searches of hard drives just discussed and searches of email accounts," he said.
Though the court considered the question of whether Google employees could be asked to provide only relevant emails, in the end it ruled against it.
"Google employees would not be able to interpret the significance of particular emails without having been trained in the substance of the investigation," Gorenstein wrote.