shoot oneself in the foot按照字面意思是开枪打中自己的脚，意义很像中国俗语"搬起石头砸自己的脚、咎由自取。"换句话说是，由于粗心笨拙而打击别人不成反给自己惹来麻烦。      

【例句】
He shot himself in the foot，an undercover cop who sent him to jail.
他咎由自取，一名卧底警察把他送进了监狱。

The senator shot himself in the foot when he called his opponent names,which reflected badly on his political maturity.
那个参议员辱骂对手，显得政治上还不成熟。他是搬起石头打自己的脚了。