Smith v. Maryland only involved pen register on one person's contacts, where there was some suspicion. Each cell tower dump involved that plus location data on

Smith v. Maryland only involved pen register on one person's contacts, where there was some suspicion. Each cell tower dump involved that plus location data on at least 150,000 people, only one of which was acting suspiciously. The court decided that we expect the phone company to have that information, but we also expect them to keep it confidential if we're not doing anything wrong. The standard for sharing may be lower than we'd like, but there is SOME standard. The government could have given the phone company times and places, and asked them to perform the cross-check and return any matches. That way, only the "suspicious persons" would have had their privacy violated. Handing everything over wasn't the only way.