  We note that the energy loss in ${\cal N}=4$ SYM measures directly the
spatial string tension $\sigma_S=\pi\sqrt{\lambda}T^2/2$ which is at the origin
of the area law for large spatial Wilson loops. We show that the latter
reflects on the nonperturbative nature of Ampere's law in ${\cal N}=4$ SYM both
in vacuum and at finite temperature.
