The blurb about the price of gas is a trivial example.
But it makes the point.
A better example -- at the time of the 2003 attack on Iraq -- 70% of Americans (including the knee jerks on the OM) believed that Saddam Hussein was linked to 9/11.
A similar percentage believed that Saddam had WMDs.
Neither of which was true. Americans believed it because the US media endlessly repeated these lies. Repeat a lie enough times and people will swallow it. The bigger the lie the easier it is to swallow.