Most, if not all, major smart phone manufacturers have clauses in their user contracts which stipulate that they will share data when complying with law-enforcement. However, this potential violation of your privacy may not be as far-reaching as it seems at first.
First, to summarize: There is no short answer to whether investigators can access your smartphone data. The reality is that access would often depend on current security and infiltration technology, the manufacturer of your device, your level of cooperation with officials and the level of security you implemented, among other factors.
As you may be aware, this is not a new issue. In fact, the New York Times recently reported on a case involving F.B.I. investigators asking for device access from a certain California tech giant. This case has significant similarities to one from roughly five years ago.
Once again, the company has denied providing access on the basis that it does not have access in the first place. Furthermore, it states that it will not build such capability into the devices for fear of setting a precedent that would compromise user confidence, security and privacy.
From a criminal defense perspective, it is important that you understand that many of these tech companies have access to data that goes well beyond what you stored locally on your device. The most recognizable version of this would be photos or files you uploaded to cloud services.
Beyond that recognizable data, your phone’s manufacturer or the publishers of the applications you use may have access to information that could potentially strengthen a case against you. Understanding this exchange of data — including technical elements, such as how and when the automated reporting services anonymize the information they send — could help you form a better, proactive defense.