In November, an unknown attacker hacked the computer systems of the San Franciscos Municipal railway giving riders a free ride all day on Saturday. An individual who hacked back the Muni hacker broke into the email account by guessing the security question protecting it, then he reset the password and locked down the account and secondary address [email protected]. The hacker earned $140,000 in the last three months, a circumstance that confirms that he is a cyber criminal. Experts discovered that the hacker used a number of tools which enabled the scanning of large portions of the Internet and several targets for vulnerabilities.”]
Source: https://securityaffairs.co/wordpress/54159/cyber-crime/muni-hacker-hack-back.html