On Monday, January 3, 2011, the California Supreme Court held that the 4th Amendment permits police officers to search the contents of the cell phone incident to a lawful arrest.

In People v. Gregory Diaz, the defendant was arrested after participating in a drug sale with a police informant. The defendant was taken to the sheriff's station, where his cell phone was seized. After the defendant denied involvement in the drug deal, the deputy who arrested the defendant searched the defendant's text messages in his cell phone. The deputy's search of the phone occurred about an hour and a half after defendant was arrested. The deputy found an incriminating message in the phone, showed it to the defendant, and the defendant confessed to participating in the drug deal.

The defendant plead not guilty to the charge of selling a controlled substance, and moved to suppress the incriminating text message and his subsequent confession. He argued that the warrantless search of the cell phone violated the Fourth Amendment.

The California Supreme Court held that the defendant's cell phone was "immediately associated with [defendant‟s] person," and therefore, the warrantless search of the cell phone was valid. The Court stated that because the cell phone was immediately associated with the defendant's person, the deputy was entitled to inspect its contents without a warrant.

The dissent argued that the privacy interests in cell phones is great, considering technological advances that make smart phones similar to personal computers, and the invasion of privacy of searching these phones without a warrant is also great. The dissent stated that this type of search is highly intrusive and unjustified, arguing that it fails to meet the warrant requirement or the reasonableness requirement of the U.S. Constitution.