let's guess the reaction of different groups of people ....

1. Germans - as above
2. Americans - as above ?
3. Frogs and other continentals - put on their sunglasses and
pretend you're invisible ?
3. Canadians - they don't litter
4. other south east asians - they don't litter either, they've
all heard Singapore is a fine country
5. Japanese - dud
6. Koreans - dud too, since they like to pretend to be like the
japanese
7. Hongkies - recite your ancestral tree, in cantonese
8. PRC ?
10. Indians ?
lai lai .. see what you can add ... 
PRC: swear at them in english
Indians: Swear at them in Chinese
Malay/Muslim: shout out in english
about pork and babi