Last week I signed up for Google + (you can find me here), and one of first things I tried was to sign in on an Apple iPad.
I was annoyed to see the following message:
Google demanded the right to use my location with Google Plus, otherwise it would not let me sign in. But what if you want to use Google Plus without sharing your location with the world? Since Google Plus works fine on desktop PCs without location information, why should you not use it on an iPad in the same way?
This led me to investigate the W3C Geolocation API. In fact, I wrote my own web page to test how it works. I went over to Bing Maps, signed up for a developer account, and wrote a small amount of JavaScript to test it. You can try it here if you have a reasonably modern browser. I have not bothered to test for older browsers that do not support geolocation.
You will notice a couple of things about this test page. One is that it will ask your consent before attempting to retrieve your location. Another is that on a home broadband connection, it is rather inaccurate. According to Internet Explorer 9 I am in Berkhamsted – do not try and visit me there though, I am nowhere near.
However, if you try this on an iPad or other mobile device, you will likely get much better results. If I use the iPad, even on home wifi, it shows my house dead centre of the map.
That is only if you give consent though. Since Google + is a web application, this consent is determined by Safari, irrespective of what terms and conditions you agreed with Google. If it bothers you, you can even go to settings – location services and disable them for Safari completely:
That said, Google could add some code that tried to retrieve your location and would not let you use Google+ if access is denied – but it has not done so. In fact, so far the only time I have seen Safari prompt for consent in Google+ is when making a post:
If you agree, this allows Google+ to geotag your post.
I am sure there are other ways Google plans to use your location in Google+. For the moment though, if you would rather maintain location privacy Google+ still allows you do to do so.
I’ve found that the browser-based geolocation on the Mac can be very accurate for home broadband, if you use wireless – presumably thanks to people like Google building up their databases of wireless networks, along with the streetmap info.
Otherwise, as you say, it tends to come up with locations that are based more on the information about your ISP than anything else.
Nigel
Interesting – just tried it and you are right, even on my own wifi access point, using a Windows netbook that has no GPS. Creepy.
Tim
The good thing about those WiFi databases is you can fool them by using a directional antenna on your WiFi, as they can only assume your WiFi is beaming equally in all directions.
I find it quite comforting to know that while it still points to the area where I live, at least its not pointing right at my house because my WiFi is beaming out across the road via a Yagi antenna and so would appear to be originating elsewhere. I presume using a panel antenna could also shift the accuracy in the direction your are beaming the signal too. Although I suspect if you have neighbours on either side of you beaming WiFi too that it would be able to figure out where you are from their signal strength.