Yahoo! (YHOO) announced Monday that Bob Lord has joined the Internet company as CISO.A 20-year information security veteran, Lord was most recently CISO-in-Residence at Rapid 7. Prior to that, Lord led Twitter\u2019s information security program and held positions in product and information security at companies like Red Hat, AOL, and Netscape.This position at Yahoo! has seen a lot of churn in the past 6 months, writes ZDNet's Natalie Gagliordi. "In June, Alex Stamos left his gig as Yahoo CISO to become the CSO of social networking giant Facebook. Shortly after Stamos' departure, the CISO role was filled by Ramses Martinez -- only to have Martinez quietly abandon the position in August to join Apple's information security team."In his new role, Lord will lead Yahoo\u2019s security team -- known as the Paranoids -- in offensive and defensive protection of the company\u2019s more than one billion users around the world, and for Yahoo\u2019s employees globally.