Ransomware
I agree with the guy from Emsisoft. The law needs to be changed to (1) limit insurance to covering the cost of business interruption and system recovery, and specifically make it illegal to cover ransom, and (2) treat paying a ransom similar to paying a bribe, that is, make it illegal with criminal penalties and don't treat the payment as an expense for tax purposes.
This will obviously be difficult given the number of countries involved, but it is the only way to prevent ransonware from becoming ever more common.