As wikipedia says they are now considered tacky, but as with anything hanging from the rear view mirror they are dangerous!
Whe you are driving along with them dangling and moving about your brain gets used to them and then you do not see them swinging about, but in that same area you do not see cars pulling out of junctions, pedestrians, cyclists, the list is long.
Don't be an idiot and get rid of anything dangling from your mirror!
they arent dangling from my car mirror- i dont have a car! i was just wondering who the hell would think one day, well i have some fluff, some string and some dots, heck lets make 2 dice, wait furry dice, that could be, ooh i dunno, hung from the rear view mirror in cars. see what i mean?