“Ballistic” models are now put in doubt on the strength of the observed properties of “superluminal” components, and preference is given to “screen” models. It is suggested that active nuclei are supermassive systems, such as SS-433, with two precessing relativistic plasma jets, which flow from opposite directions into the same precession cone. In this case “superluminal” components can manifest themselves as displacements of the interaction between these jets and inhomogeneities in the circum-nuclear medium (clouds). Thus, due to isotropic production of relativistic particles in the interaction area and/or magnetic field distortions, bursts of emission may be observed not only along flows, as would be the case for BL Lacertae objects, but also at appreciable angular distances from the jets. Moreover, one may understand the observed one-sidedness of VLBI-jets on parsec scales and the symmetrical VLA-structures on kiloparsec scales as a result of random cloud hits by the precessing flows. We suggest that the observed repetition of active cycles of different objects may be caused by several cloud hits by the precessing flows of a complex multibeam structure once every 50–100 years.