The London riots of the past few days have received a lot of attention on radio and television. I was taken aback today, however, when I heard some speak of the thieving that was taking place. I have never before encountered this word used as a noun, and I suspect such usage is rare, though it may be more common in certain dialects. Technically, I suppose, thieving is actually a gerund, related to the verb to thieve, which is itself unusual. (He thieved the television sounds very odd.)
It is curious that we generally speak of thieves stealing, not thieving. It is also curious that stealer is rare. In principle, though not in practice, one can imagine this sentence: The stealer thieved the television.