...snip...
Can you explain in concrete terms how it is that Bastiat here is "benefiting so greatly from our current system"? Without assuming things about him or her as an individual.
I think people who make statements like yours are generalizing from their own case more than they realize.
Fred agrees that the incarceration of violent mentally ill is needed to protect people from violence. Fred agrees that he benefits as much as anyone else does from that protection. The specific point he disagrees with is whether or not he should have to pay for that protection.