That title should really be followed by an evil laugh but I don’t think it is us that should be doing the laughing.

Now I was reading today about a Polish start up called Belysio which is just another social networking site however it’s key differentiator is that it uses geotagging to map your location. Put simply, not only can you read about what your “friends” are doing, but you can also see exactly where they are. So much for the boss not knowing you are playing golf rather than meeting that client in London.

So there a whole load of privacy issues here although I suppose that you can always switch the service off (if you remember) but read on because this is actually going somewhere a lot darker.

Then we have another service called Tripit.

The idea here is that you just forward all your confirmation emails from your airline, hotel, car hire company etc for your next trip and Tripit will use them to create a fantastic custom itinerary which you can then access from any device. It will also allow you to add in local information for your destination such as places to eat etc.

Finally, LinkedIn now have a Tripit application so that my network can see where I will be travelling and when so that somebody can now see when I will be in the same city as them perhaps to meet up for a coffee and discuss a new business venture.

All good stuff but there is a dark side to all of this and I am not sure it has been thought through.

So with the above tools, I can now find out where one of my “friends” is going to be and for how long. I can then use Belysio to establish that they actually made it to their destination and even the route they took.

Or to put it another way.

From my connection with Fred, I know that he is mad on home cinema and lives in Watford somewhere.

I know that Fred is going to Paris next week  from his Tripit feed in LinkedIn and will be there for a few days. What this also now tells me is that Fred is not going to be at home and that his house is most likely going to be unoccupied for a few days.

Can you see where this is going?

Now knowing that he will be leaving on Monday I can use the Belysio service to see not only where he goes to on Monday but also where he comes from.

In other words I now know where Fred lives and more importantly know that his house is now empty whilst he is in Paris and that it will be empty for a couple of days.

So now is a perfect time to go round to Freds house and help myself to that 50” plasma screen he has been telling everybody about. If the neighbours challenge me as I walk down the drive with his TV I can tell them that I am just moving this screen for him whilst he is in Paris. To the neighbour, I am clearly a friend of Fred because I know so much about him.

Social networks can be a great tool and when you start mashing them together they can be really powerful but remember, whilst most of us are good guys, there are plenty of people out there who are not so ask yourself this question:

Do I really know everybody in my network well enough to trust them with this information?

I am guessing that most people have at least one person in their network who they have never met in real life.

Be careful out there.