"Once bitten, twice shy" is a suitable idiom to describe the expression on the races of many people when they hear the words U.S. visa mentioned.
提起美國簽證，許多人會露出「一朝被蛇咬，十年怕草繩」的表情。更甚者，只要一想到這洋「衙門」中，凡事皆以「懷疑」為出發點的態度，對赴美觀光，也就興趣缺缺了。