Traffic data, pen registers and searches
9 July 2007
Interesting article in the SF Chronicle (linked from slashdot):
The U.S. Supreme Court upheld the use of pen registers in 1979, saying callers have no right to conceal from the government the numbers they communicate electronically to the phone companies that carry their calls.
Federal law requires court approval for a pen register. But because it is not considered a search, authorities do not need a search warrant, which would require them to show that the surveillance is likely to produce evidence of a crime.
Full article by Bob Egelko, Judges OK warrantless monitoring of Web use.
Two issues spring to mind after reading this article. First the qualitative difference between the traffic data extracted from phone records, versus urls or emails. The latter can contain search terms, as well as data. Second the dangers of allowing material that it would be illegal to intercept on the wire, to be seized as a result of a search.