Their cell phone belongs to them, not the police, unless it's used for evidence. Police can't just search someones phone without permission and a warrant. Because for all they know, that "criminal suspect" could be innocent, hence they should need to have a warrant first, to search the suspect's cell phone.
This country was founded on the rule that people are innocent until proven guilty in a court of law. That means that all their property, physical or intellectual, needs to be protected under the same laws. If we allow one thing to be searched without a warrant, we will soon have everything available to be searched for any reason ever.
It is only fair that the system does not go through one's property or cell phone to find additional reasons to make you a criminal. It could cause a person who was not guilty of a crime to then be suspected of something else, or at the very least be mistreated because of the material in their phone.
Yes, I agree with the Supreme Court's recent decision that a cell phone of a criminal suspect cannot be searched without a warrant, because there is no immediate safety threat to law enforcement that would warrant them searching a phone. It's not like they need to check a vehicle to make sure they are safe. With no safety interest in it, they can get a warrant.
I agree with the Supreme Court's decision because it is a matter of personal privacy. I am not a criminal justice expert, but I see no reason for a police officer to have access to one's phone. The government can already check to see all the things one has done on his or her phone so i see no reason for an officer to do this. One's phone is ultimately something that many people want to be private; not something that he or she wants any officer to search through. The government has the technology to see what it needs to see.
Just my Opinion
If the Police have reason to believe that there is information about a crime in a cell phone they should be able to search it right then and there. No one should have a issue with the Police doing this unless they are trying to hide something. I would have no problem handed my phone ever any day and feel that a warrant could lead to important information being deleted.