Honestly, the most humane and least distasteful solution is to dispossess the billionaires of their billions. Not a drop of their blood need to be shed, should this be done.

The evidence so far is that the primary response of the heinously rich when they fear for their lives is to spend more or much more on their security and their politicians rather than to change their evil greedy behavior at all. Those looking for any real solution to oligarchs need to consider this fact when evaluating what should be done.