I'm hp co-founder and CTO of prezi. We learn from our mistakes, we have changed the program: To improve the program from now on we will reward bug hunters who find bugs outside of the scope provided that they do not violate our users’ information and that their report triggers us to improve our code base. We will also retroactively check to see if other reports found issues that fall into this category. More info at engineering.prezi.com/blog/2013/12/03/a-bug-in-the-bugbounty/