I avoid kleptomaniacs. As soon as I find a Sim with this characteristic I avoid them. With the Island this is hard to do - strangers come in and out of the house (which I like). So - what do kleptoman...
After reading this thread I feel like something must've caused the kleptomaniacs in my game to be nerfed down, because I haven't encountered that many burglaries. Or maybe I did but turned blind. hmm.
One thing though, I did catch a vampire sim who was breaking in stealing my sims' decorative (forgot what it was) during an invasion... have any of you had that? I thought it was impossible but then it did. :(