IPhone iPhone, the iPhone 3G must be activated in the store in most countries. This makes the iPhone 3G more difficult, but not impossible, to hack. The need for in-store activation, as well as the huge number of first-generation iPhone and iPod Touch users upgrading to iPhone OS 2.0, caused a worldwide overload of Apple's servers on July 11, 2008, the day on which both the iPhone 3G and iPhone OS 2.0 updates as well as MobileMe were released. After the update, devices were required to connect to Apple's servers to authenticate it, causing many devices to be temporarily unusable. Users
IPhone 3GS more favorable reviews mainly because it comes pre-installed with iOS 4. Jason Snell of Macworld praised the iPhone 3GS, saying that "the device's internal changes shines in the iOS 4 update, making the iPhone 3GS a worthwhile upgrade compared to its predecessor although a little too late compared to the iPhone 4." TIPB stated that "aside from hardware specific features like FaceTime, Retina Display, and gyroscope support, the bottom line is iPhone 3GS users are getting the same software that makes the iPhone 4 great." Shortly after the release of the iPhone 3GS, some users reported overheating of the device