To help understand the impact of the current debate about “phone-metadata”, or records of phonecalls, a friend cited an article that describes how a Colombian drug cartel, in 2002, used phone metadata to find government informants and kill them. Apparently, the US government has not been interested in having this known since this was after the US Patriot Act went into effect and we now know the US government has been using phone metadata to find press informants and prosecute them.
The first 5 paragraphs are the meat of the metadata issue.
(originally via John Gilmore and Bruce Stirling in 2002)