How much energy does it take to vaporize a human?

According to a 2013 study published in the Journal of Interdisciplinary Science Topics (Annals of Mad Science and the Journal of Sophisticated Villainery not having nearly as good of impact factors) it would take 2.99 GJ worth of energy to completely vaporize an entire human body. This fact should give you pause before you try to vaporize a place, rather than a person, writes blogger Kyle Hill. You'd need more than 70 of the most powerful lasers that currently exist just to off that one person. And that's not very efficient evil.