  Fast (~1000 km/s) outflows of neutral gas (from 21-cm HI absorption) are
detected in strong radio sources. The outflows occur, at least in some cases,
at distances from the radio core that range between few hundred parsecs and
kpc. These HI outflows likely originate from the interaction between radio jets
and the dense surrounding medium. The estimated mass outflow rates are
comparable to those of moderate starburst-driven superwinds. The impact on the
evolution of the host galaxies is discussed.
