Zuzak's comment is great and i wouldn't dare to suggest that I could do a better job - I just want to hammer on the point that you are not the agent of karma
when I say you, i don't mean you DragonWasabi, or you DragonWasabi's friend, i really mean anyone. especially in most Buddhist schools, there really isn't a "distributer of karmic justice" or what have you. it's just, as i understand the Buddhist perspective, a force of nature and it is how it is. it doesn't need an agent, and acting as if one is that is almost certain to worsen one's karmic load, hence ahimsa.
disclaimer that i myself do not identify as Buddhist or anything resembling a Buddhism expert. i took one intro to Buddhism class in college and that's all i've got.
it looks so cute tho