There are a group of hackers called the "Turkish Crime Family" who have threatened Apple saying they would delete 200 million iCloud accounts if Apple did not pay a ransom of $75,000 or $100,000 in iTunes gift cards (that's a lot of music, huh?)
Motherboard reported on this and got in contact with some of the hackers that apparently are threatening Apple with this. They have uploaded YouTube videos which showed them scrolling through accounts that they apparently hacked.
Source: Twitter
Above is a tweet they also sent out to let everyone know that they are serious. While there are some inconsistencies in the story, I'm sure they are taking this serious but Apple hasn't commented on the hacking. If this is true though, the hackers say they will wipe the accounts April 7th. Lets hope this is a prank for the sake of everyone who has a iPhone!