Attempts have been made to control dictionaries by big business, but actually the dictionaries themselves tend to resist this. So when McDonald's tried to get one dictionary to change its definition of the phrase "McJob" (a low-paid menial job with no good career prospects), they merely demonstrated that they failed to understand what a dictionary is actually for.
I think it would be more worrying to have dictionaries under government control (directly or indirectly). Totalitarian governments sometimes try to control how language is used, because in doing so they think they can control how people think. This was taken to its logical conclusion in George Orwell's novel Nineteen Eighty-Four, where the government was planning to change the language so that people would be unable to talk about certain subjects because they didn't have the words for them.