Zerodium mentioned, “Apple iOS, like all operating system, is often affected by critical security vulnerabilities, however due to the increasing number of security improvements and the effectiveness of exploit mitigations in place, Apple’s iOS is currently the most secure mobile OS. But don’t be fooled, secure does not mean unbreakable, it just means that iOS has currently the highest cost and complexity of vulnerability exploitation and here’s where the Million Dollar iOS 9 Bug Bounty comes into play.”
Zerodium will not disclose their vulnerability findings to affected companies, no matter how “large” a brand it is. Rather, it tends to sell the findings to the highest bidder. One risk from this is, it can be rather difficult to keep track of things, especially to who or where the exploits were sold, and should it end up in the wrong hands, the world might end up poorer for it, especially when you have more than 50% of iOS devices running on iOS 9.