The answer is yes, at the present time. I explain below.
The heart of the answer to your question is in the Fourth Amendment to the US constitution:
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
The IVth amendment speaks about individuals right to privacy and usually refers to governmental agencies. Below is an excerpt by Orin Kerr a professor at law at XXXXX XXXXX University. The discussions about this issue have all centered on whether the police (governments) have the right to read someone text messages or pager messages. The 5th Circuit court has held that a search of cell phone text messages by the police as a search incident to an arrest as lawful. Other federal circuits have not taken up the issues at this time; therefore, this is the prevailing law at the present time.
Additionally, in theory, at issue is if the text message was observed to be in plain view and in an area that the police (government) had legal access to either by search warrant (for un-related issue) or by consent then the reading of the text message would also be justifiable. However, due to the fact that text messages are stored electronically the only way I can see this fact pattern occurring is if someone handed their cell phone to a police officer and allowed them to look through it or the officer had a search warrant for the cell phone. I included this merely as additional information for you.
I hope this helps you and thank you for visiting JustAnswer for assistance.
So what about the text messages? XXXXX XXXXX University Law Professor Orin Kerr tackled this question, arguing that unlike the phone numbers dialed and recorded in Smith, and unlike the pager-signals used to track the defendant's movement in Knotts, text messages represent content. This crucial distinction seems to tip the balance in favor of an individual's legitimate expectation of privacy. That theory is buttressed by the Fifth Circuit's opinion in U.S. v. Finley that one has a "reasonable expectation of privacy" in one's cell phone text messages as well as numbers; on the other hand, due to the "search incident to arrest" doctrine, the Court still held the search to be lawful - and other federal circuits have yet to address the issue.
So why does the extension of this doctrine raise so many questions?
As it becomes easier to utilize technology, the balance between government interests and individual privacy becomes harder to navigate. The situation may be less dire or alarming than many stories suggest, but the fact remains: as our access to information grows in speed and scope, the avenues a government actor has to reach evidence grows right along with it. Nowhere is that more true than during an arrest: if Fourth Amendment jurisprudence follows the Court of Appeals of the Fifth Circuit in viewing phones and other digital devices as akin to Tupperware stash-boxes, an officer engaged in an otherwise lawful arrest could potentially browse a driver's text messages without fear of violating constitutional protections. Although not everyone has 14,000 salacious texts to a chief of staff to worry about, it's a thought-provoking idea nonetheless - and one that brings into clear relief the questions raised as personal digital technology and the Fourth Amendment continue to cross paths.