I'd have to agree with Leading Edge, I've got a particular down on third party wannabees, especially the outfit in Melbourne who are a drain on the industry. The operator(s) who support them are equally foolish, allowing it to happen. One of these fringe dwellers, who became a real pain some 10 years ago, caused all sorts of problems for the industry at large, and CASA was totally ineffective in dealing with him.
As non holders of AOC's the whole set up is often legally doubtful, but it's so much easier for CASA to chase up operators/pilots who have exceeded their duty times by 15 minutes
And as for aerial banner towing, we do it all the time. Tail rotor is never the problem, but a close inspection of the MGB mounts (and spike in the 206) is often called for, the drag from the larger flags is quite extreme. I flew the largest flag ever under a 117 a couple of years ago, and 35 knots was flat out!
http://www.helicopterservice.com.au/...17_gp_flag.jpg