The media and marketers manipulate the public in many different ways. Firstly, the media tries its level best to show the public only what it wants the public to see. Say for instance I own a news channel, I have the authority to choose what to report about and what to ignore.
Similarly, marketers often tend to misguide the public about specific products, and media propagates those ideas in the form of advertisements that are paid for. There have been cases where many products have been banned due to the presence harmful chemicals, and it was the media through which the products were being advertised.