In a court ruling, Judge Richard Posner took the lead in an appeals court ruling that effectively reaffirmed the idea that police don't need a warrant to search mobile phones as is to arrest a person. But this particular ruling does seem pretty limited. While Posner basically compares the phone to a diary, and focuses on the mere searching of basic data, like the address book, to suggest this particular search was limited, and doesn't raise any significant 4th amendment issue.
It’s not even clear that we need a rule of law specific to cell phones or other computers. If police are entitled to open a pocket diary to copy the owner’s address, they should be entitled to turn on a cell phone to learn its number. If allowed to leaf through a pocket address book, as they are, they should be entitled to read the address book in a cell phone. If forbidden to peruse love letters recognized as such found wedged between the pages of the address book, they should be forbidden to read love letters in the files of a cell phone.
Effectively, the court more or less says that circumstances matter, and that in situations where there's a chance that data will get deleted or modified, it's perfectly reasonable to do a simple search of the mobile phone, but it could get thornier if it moves more in the direction of voyeurism, rather than as evidence for crimes. I'd certainly prefer much stronger privacy protections -- especially as a phone really is a window into much, much more than just a phone, but the ruling isn't much of a surprise and seems to align with other rulings on similar issues.
