Although Apple will not substantiate claims that the Turkish Crime Family has the usernames and passwords of hundreds of millions iCloud and Apple email accounts, your Apple ID password should be changed as soon as possible, and certainly should be changed prior to April 6 if you use one with your iPhone, iPad, or other Apple device. The Apple ID would be associated with Me.com, iCloud.com, Apple email accounts, and iTunes store accounts.
This is also serves as a good reminder to update the Apple ID password on a regular basis as a precautionary practice against hackers.
For information on how to change the Apple ID password: https://support.apple.com/en-us/ht201355
For more information, check out the following article: