1. A lot. I work in the warehouse of a pretty large construction company and everyone in a while we get some fire extinguishers back from job sites that no longer will pass inspection. so we empty them and scrap the metal. no fire extinguisher that i have ever seen looks like a fog machine when it is going off.
2. I doubt the police would agree to something like that because what happens in the instance that someone really does pull out a gun or some something of that nature and the police are really needed? Though i can't say for a fact that the police wouldn't agree to this, it just seems kind of ridiculous.
3. What happens if someone jumps in to try and help and ends up getting injured. or what if the panic you cause people gives them a heart attack. or shit, people could just sue for made up traumatic stress that the situation caused. you can't just pull shit like this without people signing liability wavers/consent forms. some nobodies doing this for fun sure, but not a marketing company working with a major Hollywood movie.
4. let me rephrase that one. everyone in the video that attempts a physical intervention does it by some ridiculous theatrics
My points at at the very least decent, so i should feel ok