"No Dumping"
Dumping can refer to at last 3 different types of things and none of them are any good:
1) Dogs - When people are inconsiderate with the animals and they take a "dump" and people don't clean up after them (leaving the messy stink for you to step in).
2) Trash - When people throw their trash in the dump or what they consider to be a convenient dumping ground and they make a huge mess of the surroundings (like the used mattress on the side of the road).
3) Emotions - When people dump their emotions and problems on others; they just sort of let it all out and while they may feel better (i.e. a nice catharsis), now you feel like sh*t!
Overall, I can't think of any good connotation to dumping, so maybe people should stop doing it--dogs, trash, and problems. ;-)
(Credit Photo: Andy Blumenthal)