WASHINGTON – Twitter’s former security chief told Congress Tuesday there was “at least one agent” from China’s intelligence service on Twitter’s payroll and that the company knowingly allowed India to add agents to the company roster as well, potentially giving those nations access to sensitive data about users. Zatko told lawmakers that the social media platform is plagued by weak cyber defenses that make it vulnerable to exploitation by “teenagers, thieves and spies” and put the privacy of its users at risk. “I am here today because Twitter leadership is misleading the public, lawmakers, regulators and even its own board…