The answer may vary between cellular providers, and the area is moving quickly, both as to technology and as to the applicable laws, but the past few subpoenas we have served have been returned with a notation that the data no longer exists after days, or weeks. Sometimes it is possible to get "metadata" (basically information about whether, how much, how long, and from where messages were sent) even if you cannot get the texts themselves.
Answered on Oct 11th, 2014 at 1:41 PM