Snowden documents could be 'worst nightmare' for U.S. -journalist

BUENOS AIRES (Reuters) - Fugitive former U.S. spy contractor Edward Snowden controls dangerous information that could become the United States' "worst nightmare" if revealed, a journalist familiar with the data said in a newspaper interview.

Glenn Greenwald, the Guardian journalist who first published the documents Snowden leaked, said in a newspaper interview published on Saturday that the U.S. government should be careful in its pursuit of the former computer analyst.