  To accommodate the seemingly "anti-hierarchical" properties of galaxies near
the upper end of the mass function within our hierarchical paradigm, current
models of galaxy evolution postulate a phase of vigorous AGN feedback at high
redshift, which effectively terminates star formation by quenching the supply
of cold gas. Using the SINFONI IFU on the VLT, we identified kpc-sized outflows
of ionized gas in z~2-3 radio galaxies, which have the expected signatures of
being powerful AGN-driven winds with the potential of terminating star
formation in the massive host galaxies. The bipolar outflows contain up to few
x 10^10 M_sun in ionized gas with velocities near the escape velocity of a
massive galaxy. Kinetic energies are equivalent to ~0.2% of the rest mass of
the supermassive black hole. We discuss the results of this on-going study and
the global impact of the observed outflows.
