Just my $0.02 on sandbagging...


I had always thought that to sandbag someone meant to ambush them in one way or another, and the origin was from the use of sandbags in theaters. Sandbags were (maybe still are) used as counterweights on pullies, to hold up the large backdrops and other set pieces used on stage. By cutting a rope a sandbag could be made to fall vertically onto an unsuspecting passer-by. Thus the heavy sandbag would drop upon the person with calamatous effect, and the person would never know what hit them.