Cyber security expert Tony Grasso joins Kathryn to talk about some big hacks or Dedicated Denial of Service attacks, including the one on the NZX, a ransomware attack on gaming blockbuster Cyberpunk 2077 and the near-successful attack on a water treatment plant in Florida which would've pumped sodium hydroxide into the city's water. Tony Grasso is Principal Consultant at cybersecurity firm TitaniumDefence. He worked at GCHQ in the UK and is a former Intelligence Officer in New Zealand.