Dorner claimed Williams was harassing him and sent a threatening letter to his home.

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In 1967, the year Lillehei left Minnesota to become chief of surgery at New York Hospital-Cornell Medical Center, the IRSsent a threatening letter.

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We recently had a threatening letter from our local authority in an attempt to dissuade us from taking children out of school for holidays and stating the importance of the children not missing school.

BBC: NEWS | UK | Education | Girl expelled over term holiday

Earlier in January, Nasdaq sent them a letter threatening to delist the stock for having a stock price below a dollar.

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In Washington state, a 37-year-old was charged last week with threatening to kill a federal judge in a letter that contained ricin.

WSJ: Union: NY mayor threats postmarked Shreveport, La.

It will send these taxpayers a letter telling them to disregard the previous threatening notice.

FORBES: You have the right to be terrified

It is not easy to explain to a single mother who recently lost her job, or a veteran returning from serving our country, why their bank is sending them a letter offering to modify their loan one day and threatening them with eviction the next.

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"The uncomfortable reality of our world today is that bits and bytes can be as threatening as bullets and bombs, " Dempsey said in a letter Wednesday to Sen.

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This past August, more than 90 U.S. senators signed a letter to President Barack Obama pressing him to sanction Iran's central bank, with some, threatening legislation to force the move.

CENTERFORSECURITYPOLICY: Center For Security Policy