Moxie Marlinspike founded Whisper Systems, which was acquired by Twitter in 2011. He is one of the more well-respected and innovative minds in the security community. Twitter has been addressing a number of security and privacy issues in the last few months. In September, Charlie Miller joined Twitter s security team, working directly under Marlinspikes. In a message posted on Twitter, he said today would be his last day at the company and later said that he would be taking some time off to relax.
Source: https://threatpost.com/moxie-marlinspike-leaving-twitter-security-team-011113/77400/