I don't approve of his motives or actions either, but still, it seems that spending years in jail is a disproportionate punishment for the amount of harm he may have caused AT&T or its customers. This article says that they had second thoughts about how smart their plans actually were and ended up deleting the data rather than selling it to anybody. And it's doubtful that their actions had any lasting effect on the stock price of AT&T - data leaks are a fairly frequent occurrence among large corporations.