according to a 2004 General Accounting Office report, the Bush administration and the Pentagon continued to rely heavily on data-mining techniques. "Our survey of 128 federal departments and agencies on their use of data mining," the report said, "shows that 52 agencies are using or are planning to use data mining. These departments and agencies reported 199 data-mining efforts, of which 68 are planned and 131 are operational." Of these uses, the report continued, "the Department of Defense reported the largest number of efforts."
Ross Anderson has some interesting questions about the situation in the UK (with some partial answers from me), where GCHQ is no doubt undertaking similar activities. Douwe Korff and I wrote an extensive report for the Information Commissioner in 2003 about these technologies and how law enforcement agencies should be regulated in their use.