A review of the experimental observation of plasma net currents in several stellarator devices and the comparison with theoretical predictions on the neoclassical bootstrap current is given. Good agreement of the experimental findings with neoclassical predictions is found with respect to the parameter dependence, the local distribution of the currents and the magnitude. The compensation of the bootstrap current by electron cyclotron current drive is experimentally demonstrated. Experiments on the ECCD-efficiency are compared with simple theoretical models.