It's great that the EFF has outlined this material in such detail, but, as with many issues of legal epistemology, we need to remember that the state has an interest in <i>not understanding</i> these things, and it will continue to fail to understand until political pressure forces a different course.<p>A similar example: the tests used to detect the presence of certain chemical substances ("narcotics field tests") are laughably unreliable[0], but police agencies across the USA continue to use them, and courts continue to accept their results as probable cause.<p>It is not difficult to explain to someone, in under 5 minutes, why IP addresses are insufficient to determine either identity or location, but the state chooses not the understand this information.<p>That is its nature, and also the reason to be optimistic that it is subject to deprecation in the information age.<p>0: <a href="https://www.washingtonpost.com/news/the-watch/wp/2015/02/26/a-partial-list-of-things-that-field-testing-drug-kits-have-mistakenly-identified-as-contraband/?utm_term=.fd172f07aa99" rel="nofollow">https://www.washingtonpost.com/news/the-watch/wp/2015/02/26/...</a>