In response, Shell filed lawsuits to seek injunctions from possible protests, and Benjamin Jealous of the NAACP and Radford argued that the legal action was "trampling American's rights." According to Greenpeace, Shell lodged a request with Google to ban video footage of a Greenpeace protest action that occurred at the Shell-sponsored Formula One (F1) Belgian Grand Prix on 25 August 2013, in which "SaveTheArctic.org" banners appear at the winners' podium ceremony. In the video, the banners rise up automatically—activists controlled their appearance with the use of four radio car antennas—revealing the website URL, alongside an image that consists of half of a polar bear's head and half of the Shell logo.
Try to answer this question if possible (otherwise reply "unanswerable"): How were the winners' podiums controlled?
unanswerable