Either: 1) they made more of a profit than they officially reported and failed to kick upstairs, or 2) TPTB have found somebody else that they think can wring just a little more blood out of the stone, or 3) competing interests saw a chance to cut them off at the knees and move in on them. Any time government ministers in China started get a little *too* grabby, their fingers got a little *too* sticky, the emperor would execute a couple of them, both to help mollify the upset peasantry, and to send the message to the rest to get their greed back under control. This technique was called: "Killing a chicken to frighten the monkeys."