  We present a new measurement of the linear bias of radio loud active galactic
nuclei (RLAGN) at $z\approx0.3$ and $L_{\rm 1.4GHz}>10^{23}\,{\rm W\,Hz^{-1}}$
selected from the Best & Heckman (2012) sample, made by cross-correlating the
RLAGN surface density with a map of the convergence of the weak lensing field
of the cosmic microwave background from Planck. We detect the cross-power
signal at a significance of $3\sigma$ and use the amplitude of the cross-power
spectrum to estimate the linear bias of RLAGN, $b=2.5 \pm 0.8$, corresponding
to a typical dark matter halo mass of $\log_{10}(M_{\rm h} /h^{-1}
M_\odot)=14.0^{+0.3}_{-0.5}$. When RLAGN associated with optically-selected
clusters are removed we measure a lower bias corresponding to $\log_{10}(M_{\rm
h} /h^{-1} M_\odot)=13.7^{+0.4}_{-1.0}$. These observations support the view
that powerful RLAGN typically inhabit rich group and cluster environments.
