Improve your french: What is to have a GRANDE GUEULE?

   French people are used to qualify as "Grande Gueule" anyone who thinks he is at a higher position than the person in front of him/her, higher enough to give himself the right to give advice, to shout out advice or commands, like a barking dog.
   Here is the best illustration ever, of what is "avoir une grande gueule", to have a BIG MOUTH.
   A year ago, day for day, UK was hit by riots in some of its cities. It seemed, from a french stand point, that the police who happened to be overwhelmed by demonstrators, suffered from unnecessary injuries. The french police by then, purposed to "help" their Brit counterparts, with a somewhat contempt.
   This week, far worst "adventure" occurred on Amiens, an average city of France. 7 hours around the clock, french police, about 150 elements, hardly stopped the spreading of violence across the city, resulting in 16 policemen got wounded seriously. V experts got overwhelmed...
   It's always a VERY BAD IDEA to publicly provide advice to foreigners when no one asked you to do so. But will this case prevent such a "Grande Gueule" France, from changing its feeling of being V EXPERT in so many domains of public actions? Definitely NO, IT WON'T!