From seeing scam pranks on youtube. You get a scam call center telling you to install teamviewer or something. They run netstat and open the event viewer, tell you your pc has hundreds of errors and people spying on you. If you're lucky they run syskey [0] as form of ransomware. In the end they ask $200 to fix your pc.

[0] https://en.wikipedia.org/wiki/Syskey