  We report the experimental observation of the interaction and attraction of
many localized modes in a two dimensional (2D) system realized by a disordered
optical fiber supporting transverse Anderson localization. We show that a
nonlocal optically nonlinear response of thermal origin alters the localization
length by an amount determined by the optical power and also induces an action
at a distance between the localized modes and their spatial migration. Evidence
of a collective and strongly interacting regime is given.
