Even though the Crazyflie is just a small quadcopter it can still do damage in a number of different ways. Therefore it's important to operate it in a responsible way making sure that safety comes first. The hardware is still in a prototype/experimental state and the firmware/software is still unstable and undergoing changes by both us as well as the community. This means that the Crazyflie will sometimes behave very unexpectedly and this might cause problems.
The Crazyflie is NOT a toy and should be operated responsibly. Use common sense and take the proper precautions.
The safety of people should have your highest priority! Keep a safe distance between your Crazyflie and living objects!