Umbrellas are an unusual source of entertainment in Taiwan. No other place seems to have an umbrella etiquette quite like it (or, for that matter, quite so much rain). They seem to be an institution in their own right.
On rainy days, most people will obligingly place their wet umbrellas, unmarked, in or beside stands outside before entering any store, market, or other public space in Taipei. In urban metropolis's across the US, China, or Europe, this would be unheard of - they would disappear in a second.
Meanwhile, in Taiwan, umbrellas that are left unguarded in scattered piles outside rarely get stolen. Even MRT stops occasionally have umbrella stands near their toll booths with nondescript umbrellas for passengers and commuters to take and return as they please.
If umbrella etiquette were a measure of progress in society, Taiwan would surely lead the way.