There are (or rather, were) websites that we can access when we want to know, for example, if there is a planning application near us. There are websites that can take the information about jobs available through the Job Centre and send us that information.

It is that very special feature – being postcode driven, so that information can be given in the geographical locations we want – that makes them so useful. This dissemination of useful information, driven by postcodes, is beneficial forgot just for individuals but for the country.

But the Royal Mail has decided that only it can use postcodes – even if as in this case – it is not for profit and for human good.

The Royal Mail threatened to take a case against Ernestmarples (which underpins a range of valuable different website services) on copyright grounds. Obviously – this is David and Goliath – and Ernestmarples could not afford to take on the might of the Royal Mail and so have closed down their site.

But we all need to join in this fight. I was asked my views – and here they are:

As Chair of the Liberal Democrat Technology Board – and an MP who believes that the internet should be used to strengthen democracy – I want to declare my support for the Free our Data campaign.

We need postcodes to be owned by the public – not sold to the public. Postcodes are the basic pre-requisite for allowing services to be developed that support democratic accountability.

As an MP, sites like MySociety and others are revolutionizing our accountability and the accountability and accessibility of Parliament. But they currently have to operate on the edge of legality – and if our postcodes were set free – could and would be right at the heart of a new politics – an open and accountable politics.

This is an issue that cuts across parties – hence Labour MP Tom Watson talking about it on Lib Dem Voice – and so it should, because it’s about how the data about us can help us all.