so I think due to anonymity the attackers find the path easier to ask for bitcoin instead of real money.
Ransomware is difficult to clean if they get into various formats such as mpg, pdf, and mp3. It takes data that's completely new - data backup on an external/portable hard drive. Antivirus like hitman pro and variety of premium antivirus can prevent it. But nothing could help when virus is already in hardware system, except reinstall the system.