Previously, we stated that the contents and data stored in your cellular phone is protected by the Constitution; that regardless whether your cellular phone is considered a dangerous weapon or have been used to commit an offense, the contents or data stored in it may not be searched without a judicial warrant.
That while it may be legally possible to conduct warrantless search of the physical cellphone itself, the legality of searching without a judicial warrant the contents or data in a cellphone is another thing. Any police officer who wants to search the contents or data stored in your cellular phone must first obtain a judicial search warrant.
In the case Riley v. California, the United States Supreme Court answered the question of what police must do before searching a cellphone seized incident to an arrest: get a warrant.
This foreign jurisprudence is important because Philippine Courts often look at US jurisprudence for analogous cases in deciding similar questions of law.
For full text of the Riley decision, see http://www.supremecourt.gov/opinions/13pdf/13-132_8l9c.pdf.
So when you are arrested, or about to be arrested, and the arresting officer or person asks “may I take a look at the contents of your cellphone” or “can you please unlock your cellphone”, your answer should be “no, you cannot search the contents of my cellphone, get a judicial warrant” or something like that.
PS: In page 9 of the Riley decision, the author of this article has yet to verify whether the proverbial visitor referred to in the decision is marvin.