Director explains the program and strategy -
‘One of the best ways to protect our members is by identifying vulnerabilities prior to launch through a careful design review and pre-release testing. In this rapidly changing environment where we ship code multiple times a day, we also keep an eye out for vulnerabilities in production.
Our strong relationship with the security community is crucial to this process and we appreciate the work of individual researchers who contribute their expertise and time to make LinkedIn a safer place for our members. In October 2014, we formalized this partnership with the creation of LinkedIn’s private bug bounty program’
Read Cory Scott’s full article here - http://engineering.linkedin.com/security/our-private-bug-bounty-program-reducing-vulnerabilities-leveraging-expert-crowds