Have you ever broken a racket NOT on purpose? I've done it twice during my 4 and a half years of play. First time I served and my racket flew out of my hands and crumbled at the head. The second time (which was a few weeks ago actually) the same thing happened but I had forgotten to put on a new tourna grip...so I learned my lesson the hard way....please don't do the same thing I did =P
Haven't broken a modern racket, but shattered some wood ones when I was a kid on framed overheads, first my faithful Futibaya High Shot and then Garcia.