One of the biggest changes introduced in iOS is the fact that your data can be protected by passcode. Interestingly even the Apple cannot access this passcode. In iOS7, if a law enforcement agency asked Apple to break in, it would do so and access your data.
With the new iOS8, Apple made it clear that even the company cannot break into your phone. However it shall be noted that data stored on iCloud is still prone to investigation and Apple would fully cooperate with the law authorities if they want to peek into your iCloud’s data.
Apple made it clear on their new privacy website that,
We have never worked with any government agency from any country to create a backdoor in any of our products or services. We have also never allowed access to our servers. And we never will.