One of the biggest questions about Big Data is who owns it?  You might say it is a Cloud that hangs over the subject matter.

The reason that the answer to the question of who owns Big Data is so important can be gauged by the economic value that is invested and stored in the subject matter.  Any asset class that is worth trillions of dollars (as Big Data is) should, you would think, have a pretty clear root of title in legal terms.  You would be wrong.

The recent case of Google Spain and Google Inc v Agencia Espanola de Proteccion de Datos ofMario Costeja Gonzalez decided by the Court of Justice of the European Union in May 2014, made it clear that an individual has the right to request the removal from an internet search engine of information which relates to that individual, and that the individual's right to data protection "will override the economic interest" (i.e. the property right) "of the operator of the search engine".  There are exceptions set out in the judgment relating to the interest of the general public in having access to information where the individual has a role in public life but for the purposes of considering the ownership rights in the data we will not concern ourselves with this aspect of the judgment.  The point which comes clearly out of the judgment is that the search engine's rights to process data about individuals is severely circumscribed by the individual's right to control the use of his own personal data.  You might say there are competing economic interests in the same piece of personal information:  the internet search engine has a right "in rem" (against the rest of the world) in connection with the investment it has made in the collection, arrangement and accessibility of its Big Data.  The individual, on the other hand, has a right "in personam" to require the "in rem" rightholder to modify the contents of its Big Data insofar as the information relates to him.  And the in personam right will usually trump the in remright.

In these circumstances it can be seen how tenuous the ownership rights of the Big Data rightholder turn out to be.  It is intriguing how little control businesses have over what can be their most prized asset.  An illustration of this phenomenon was given when Facebook sought to change the rules it applied for the use of the personal information of its users last year.  There was an outcry from its user base which threatened to leave the site en masse.  In other words, Facebook faced the evaporation of its Big Data and, potentially, its very existence.  In the face of this threat, Facebook took the only rational course open to it and retreated on the proposed change to its usage policy.

The law which underpins the above analysis is to be found in two European Directives from the 1990s:  the Data Protection Directive 95/46 and the Database Directive 96/9.  The latter makes clear in its Article 13 that the "sui generis right" envisaged by the Directive will not prejudice other rights such as copyright, data protection and privacy.  Partly because these are still relatively recent legal developments, but mostly because they are just regional in their application and so have not had to be considered in any great depth in the main engine room of Big Data, the USA, the ramifications of the dichotomy in the proprietorship model of Big Data have yet to be fully explored.