From Greenwald’s new article:

Other documents seen by the Guardian further demonstrate that the NSA does in fact break down its surveillance intercepts which could allow the agency to determine how many of them are from the US. The level of detail includes individual IP addresses.

IP address is not a perfect proxy for someone’s physical location but it is rather close, said Chris Soghoian, the principal technologist with the Speech Privacy and Technology Project of the American Civil Liberties Union. “If you don’t take steps to hide it, the IP address provided by your internet provider will certainly tell you what country, state and, typically, city you are in,” Soghoian said.

This is just completely simplistic and wrong. Your IP address does NOT “certainly” tell anyone your country, state or city. There are tools to look up this information but they are very often incorrect. And this:

IP address is not a perfect proxy for someone’s physical location but it is rather close…

…is also just flat wrong. Some IP addresses may help determine physical location, but lots and lots of them don’t, or at best will tell you something so general that they’re not very useful for finding people.

Even if you postulate that the NSA has access to better IP/location databases, this stuff changes constantly, and people who want their locations to be private have many options to mask or obfuscate their IP addresses - for example, the TOR system.

What crap.