The amount of data Facebook holds on its users is often a cause for concern for some people, however the sociological aspects of all this information can be fascinating. In an article published today, the company looks at the concept of "six degrees of separation" — an idea first coined back in 1929 that everyone in the world is linked by just seven relationships — and compared this to the 721 million active Facebook users who between them hold 69 billion friendships. Using these relationships, Facebook was able to calculate that the average in 2011 is 4.74 steps, as compared to 5.28 just three years ago — far less than the 7 hops required for six degrees to hold true. As Facebook puts it, when considering even the farthest flung user, "a friend of your friend probably knows a friend of their friend." This already small world is only getting smaller.