How did FBI recover ransomware in the Colonial Pipeline hacking

In this episode of Talking Science & Tech, we discuss the cyberattack on Colonial Pipeline. In this case, the FBI was able to recover the majority of the ransom Colonial Pipeline paid in the form of bitcoin to cyberwarfare group DarkSide. How was the FBI able to do this? Moreover, with a rise in such hacking incidents and cyberattacks, what needs to be done to increase cybersecurity?