This chapter tries to find answers to the questions whether the fingerprint recognition is really so reliable and secure. The most biometric systems based on fingerprint recognition have very low error rates, but are these error rates really telling us everything about the quality of such a biometric system? What happens when we use spoofs to deceive the biometric system? What happens when the genuine user has any kind of skin disease on his fingertips? And could we acquire a fingerprint with acceptable quality if there are some distortions on a finger or there are some environmental effects influencing the scanning technology? Reading this chapter brings you an introduction of preparation of finger fakes (spoofs), spoof detection methods, summarization of skin diseases and their influence on papillary lines, and finally the environmental effects are discussed at the end.