Given that a large portion of people on PPRUNE appear to hate it when a passenger (sorry - SLF) or other non-pilot tries to comment on some of these matters, to some of us with a basic knowledge, it does seem obvious that this is dangerous.
Now, a non-pilot is sitting by the window over the wing which is covered in an inch of snow and he can hear the engines spooling up. What is he/she supposed to do? Make a fuss like some people have suggested? Or bite their tongue and hope for the best?
There may be many things that appear to be dangerous to a non-pilot and I don't think that any of you pilots would appreciate non-pilot passengers voicing their concerns all the time.
It is possible that the person filming the original video wanted to say something.. but somehow felt he couldn't.... What about the guy in the second video? He KNEW it was wrong and didn't say anything? Why is that?