There is a simple bug that allows anyone to bypass the new iOS 7 lockscreen, access multitasking, and view photos. The bug is present on both the iPhone 4s and iPhone 5, as well as the iPad. Apple released iOS 7.0.2 today to fix this exploit.
http://gizmodo.com/anyone-can-bypass-your-ios-7-lockscreen-to-see-and-sha-1350617707