A study by researchers from Australia’s ICT research centre NICTA revealed in 2012 that geolocation based on IP addresses alone is off by 100 km in approximately 70 per cent of all cases. With regular broadband, it is possible to have more accurate predictions, but since mobile data is, well, mobile, it means that the user moves around quite a bit. If you roam in another country, for example, your IP will still register you as being in the country of your operator.
In other words, for consumer monitoring or surveillance purposes, IP address location data is worthless.
So why does turning on wifi make location data more accurate? Because turning on wifi means turning on the device’s access to a database on wifi access points and radio towers. So-called Wi-Fi-based positioning systems (WPS) are maintained by different companies, most notably Google, Microsoft and Apple. On the plus side, your phone gets an accurate location read even though you’re inside a building. The downside? You get tracked even though you have your GPS turned off and you’re not connected to a Wi-Fi network, but simply have your phone’s Wi-Fi on.
In some cases, the phone keeps tracking networks even though Wi-Fi is off. Google does acknowledges this with the following statement:
“To improve location accuracy and for other purposes, Google and other apps may scan for nearby networks, even when wifi is off. If you don’t want this to happen, go to advanced > scanning always available.”
If you have a Google account, it could be worth checking out where you’ve been the past year through Google’s location history service.
In light of this, it becomes clear that any data retention laws that governments might have pale in comparison with the data retention gathered as a part of services provided by Google, Apple or Microsoft.