The change consists primarily of new warnings when certain changes are made to an account, as well as implementation of two-factor authentication on iCloud accounts, Cook told WSJ.

The leak of racy celebrity photos in the past few days put the company in the unusual position of having to mend its image just days before a highly anticipated September 9 product launch.

Nude photos of Hollywood celebrities, including Oscar-winning actress Jennifer Lawrence, posted on Internet forums by unknown hackers has sparked condemnation from stars and their publicists, and prompted an investigation by the Federal Bureau of Investigation.
               
In the wake of the breach, cybersecurity experts and mobile developers have called out inadequacies in Apple's and, more generally, cloud-services security. Thousands have taken to Twitter to express their frustrations with the company.
               
Some security experts faulted Apple for failing to make its devices and software easier to secure through two-factor authentication, which requires a separate verification code after users log in initially. The process requires several steps and more than rudimentary knowledge of a phone's workings.