Edit: Also the post says up to 20 years .. not sure why you've become fixated on it being simply 20. People dropping planes out of the sky for likes need to be made an example of imo, and I personally would be happy to see him locked up for life as a deterrent to others. The lengths people are going to for likes is frightening.
The biggest problem with deterrence is it relies on people not thinking they won't get caught. Everyone thinks they won't get caught.