I understand why this is so concerning. The fact that tech companies build such detailed profiles of users’ daily activities and whereabouts is a great help to law enforcement, But in order to find a suspected criminal, police often have to comb through innocent people’s information, which could result in police viewing sensitive information about a person when it's not pertinent to an investigation and innocent people becoming suspects based on coincidental connections to a crime, all without a warrant. I don’t have to explain what a legal nightmare that could become.
So a number of states, including California, have recently passed privacy laws that require police to obtain a warrant to access stored data, like messages and photos, or location information from tech companies and cell service providers. Even then it’s not foolproof; because these companies have full ownership and control over the data they collect they may encrypt certain content so it can only be viewed by the sender and intended recipient. For example, Apple's iMessages and Facebook's WhatsApp are encrypted, and therefore that content is not accessible to company employees or police. But typical SMS text messages and most other forms of electronic communication are not encrypted.
In any case, in California LE would have to get a warrant to get this data, and to do so they would have to show cause that there is the belief that a crime has been committed unless it is deemed an emergency but then there is the chance the evidence might not hold up in court if obtained without a warrant the court doesn’t believe that the emergency surrounding the report was reasonable. It’s not as simple as it may appear, especially in light of these new laws.