Having an IT background I've always thought this was a method fraught with inaccuracy.
Here are some articles to back up my reasons as to why.
http://whatismyipaddress.com/" onclick="window.open(this.href);return false;Since these numbers are usually assigned to internet service providers within region-based blocks, an IP address can often be used to identify the region or country from which a computer is connecting to the Internet. An IP address can sometimes be used to show the user's general location.
The problem is that these cases tend to operate with the pinpoint accuracy of a flamethrower, which is why New York Judge Gary Brown has ruled IP addresses are insufficient evidence to identify pirates, and has provided a lengthy and thoughtful explanation as to why that is.
http://www.geekosystem.com/ip-address-insufficient-id/" onclick="window.open(this.href);return false;“While a decade ago, home wireless networks were nearly non-existent, 61% of US homes now have wireless access. As a result, a single IP address usually supports multiple computer devices – which unlike traditional telephones can be operated simultaneously by different individuals.
Different family members, or even visitors, could have performed the alleged downloads. Unless the wireless router has been appropriately secured (and in some cases, even if it has been secured), neighbors or passersby could access the Internet using the IP address assigned to a particular subscriber and download the plaintiff’s film.”
http://www.adexchanger.com/the-debate/w ... -bad-idea/" onclick="window.open(this.href);return false;The EU took an active stance on IP addresses in 2008, declaring IP addresses as personally identifiable information (PII). This is an important first step because IP addresses are PII. That said, even the EU would admit that IP addresses do not always directly correlate to a given person. Laptop users frequently change IP addresses as they move from an Internet café to work, for example, and ISPs often dynamically swap out IP addresses. An IP address can sometimes only give approximate location, and may be shared across many members in an office, university, or café.
http://torrentfreak.com/court-rules-tha ... er-090615/" onclick="window.open(this.href);return false;Anti-piracy groups and lawyers across Europe are unmovable - they say that since they logged a copyright infringement from a particular IP address, the bill payer is responsible. Now a court in Rome has decided that on the contrary, an IP address does not identify an infringer, only a particular connection.
http://forum.digital-digest.com/f145/ip ... 91468.html" onclick="window.open(this.href);return false;