iCloud, iTunes, and other Apple websites are currently experiencing issues, with many users indicating an inability to access Apple services. Some users are having having trouble loading Apple's System Status page, which is not displaying any information on the outage. iTunes is displaying connectivity error messages, as is the App Store on iOS devices, with users unable to load either service.
Update 4:12 PM PT: As noted in our forums, it appears the outage is caused by a Google DNS issue. Apple services and web pages are accessible after turning off Google DNS.
Update 4:33 PM PT: The issue appears to have been resolved and all Apple services are now functioning as normal with Google DNS.
Article Link: Apple's iTunes, App Store, and iCloud Experiencing Issues [Update: Google DNS Problem, Now Fixed]