Would you want to be spotted in a cafe while you are supposed to be at work?
Businesses need to think about privacy too, thinks Bill Thompson
Although they have been talked about as the "next big thing" for several years now, 2010 does look like it will be the year location-based services become so widespread that they begin the long journey from cool new technology to disregarded utility, like e-mail, mobile phones and laptops before them.
Foursquare, Gowalla and Brightkite all offer an easy and fun way for their users to identify their location to other users and to the network, while Buzz and Twitter exploit geolocation of IP addresses and the GPS built into our smartphones to ensure that the social graph has a geographic axis.
Many tweets and status updates are already positional in some way, telling the world where someone is either directly or indirectly, and there is a general sense that knowing where you're doing something is at least as important as knowing what it is you're doing, especially when it comes to selling advertising or otherwise making money from the service that delivers the status updates.
More and more location-dependent tools and services will be launched over the coming months, each hoping to build a large enough user base to generate advertising income or be bought by one of the major players for enough money to keep the early investors happy.
The downside of this new type of sharing was beautifully illustrated by Please Rob Me, a site that showed the dangers of over-sharing by demonstrating how easy it is to mine Twitter data to determine when someone is away from home and therefore an easy target for burglary.
In a talk last week at the South by SouthWest Interactive conference Microsoft Research's social media expert Danah Boyd argued strongly that privacy is not dead and has not diminished in importance, but rather that the distinctions between private and public are different in the network age.
In particular, she contrasts what she calls personally identifiable information with personally embarrassing information and notes that these need to be treated differently because the consequences of exposure are different.
The potential for location-based services to cause embarrassment is enormous, and it goes beyond the obvious examples of revealing secret affairs or exposing children to parental scrutiny.
I know of one case in which an employee of a consultancy firm working for a client that demanded complete confidentiality tweeted that he was at their office, waiting for a meeting to begin. Fortunately the offending post was not noticed, and the person involved could be told not to do it again.
But as more and more devices add location data automatically to the updates and posts they put out, leakage of this sort is inevitable.
It can only be a matter of time before someone decides to pull together public location data and company records to produce a real time map of which businesses are currently holding meetings with each other, something which could be very embarrassing to all concerned.
The providers of the various services will no doubt argue that their systems can be configured to provide privacy and confidentiality, but as we saw recently when Facebook changed its privacy options, this is not always enough.
The default options that Facebook put in place for users who simply clicked through the dialogue box telling them about the new settings exposed almost all activity on the site to public view.
Google's Buzz got many thinking about privacy
This happens because the new forms of public space that networked computers make possible are controlled by private corporations with commercial agendas, and their interests are not the same as those of their users, whatever they may claim.
Google's decision to use frequent Gmail contacts as the starting point for the list of followers on the Buzz micro-blogging platform was motivated by its desire to grow fast enough to challenge Twitter from day one, and the consequences for user privacy were disregarded until public outcry forced a change.
Perhaps once companies start losing work because their employees are leaking all sorts of potentially embarrassing information about their movements, meetings and opinions on clients we will see some serious pressure on the service providers to offer more nuanced and effective privacy controls.
Bill Thompson is an independent journalist and regular commentator on the BBC World Service programme Digital Planet. He is currently working with the BBC on its archive project.