It was really interesting to hear Dennis Crowley (Co-founder and CEO of foursquare) discuss the status of the check-in as part of his appearance at GigaOM’s Mobilize conference a couple of weeks ago.

When foursquare was first founded the primary function of the service was to “explicitly tell a service where you are, with the intent of sharing that with other people”.

There are now over 194,000 monthly unique users of the platform in the UK alone.

However, the world of check-ins is now in a transition period where more and more of us are passively checking-in (whether we know it or not) rather than actively seeking to share this information with others.

This passive check-in can take the form of a geotagged tweet, Facebook update or even a photo with geographic information in the metadata.

This shift in how some platforms are gathering location information (such as Twitter giving more prominence to the geotag feature on its mobile app, or Path using city boundaries to auto check-in) highlights the ‘Big Brother’ issue again. Many individuals will be unaware of their own passive check-ins, and may not be happy about companies having access to data that they may deem private.

Although internet rumours suggest that only approximately 1-2% of tweets are currently geotagged, with around 80% of Twitter usage in the UK coming from mobile this figure is no doubt due to increase.

It will be fascinating to see how platforms look to integrate passive check-ins to gather data about their users, and whether this form of data collection will hit the mainstream like privacy concerns about public data on Facebook.

Jack Bennett is an Analyst at Jam.

Sources: Nielsen UKOM, Twitter, GigaOM Mobilize