These days, cell phones contain a lot of personal information, like text messages, e-mails, and even banking information.
Michael Vitiello is a professor at the McGeorge School of Law. He says the ruling is based on a precedent that said police can seize anything that might be harmful. If police were to arrest someone for buying drugs, and they found the suspect had a cigarette pack, they could find a razor blade inside. But Vitiello says that's not the case with a cell phone.
"It's a pretty significant invasion of privacy that goes beyond the original justification for the rule because if you just take the person's phone away from them the person can't really destroy any evidence in it and it can't really represent harm for the officers."