From the german chaos computer clubs yearly meeting. Linus talks about what to do and who ransoms work, how "well" the service is and briefly pros and cons of paying.
https://media.ccc.de/v/37c3-12134-hirne_hacken_hackback_edit...
Also a good one was the first part: https://media.ccc.de/v/36c3-11175-hirne_hacken