A two-part allegorical saying ([[歇后语|歇後語|xie1 hou4 yu3]]) meaning to provoke public outrage; based on a pun where the word for "manure" ([[粪|糞|fen4]]) sounds like the word for "indignation" ([[愤|憤|fen4]]); throwing a brick into a public toilet splashes everyone with waste