Hello, 

From my humble point of view, it will depend on which party is offering services via smart meter: data aggregators whose business lay the closest to the end users and TSOs look like rather likely owners to me. Perhaps even smart meter manufacturers can participate in the Smart Grid business as a permanent actor rather than just providing the electronic devices used as Advanced Metering Infrastructure.

It may depend on the regulations in the country.  For Australia, it was the distribution operators that owned the meters.  This has recently been opened up to third parties who may not necessarily be distribution operators or retailers.  The (household) customer doesn't own the meter, but does have access to the consumption data recorded.  The value of the data to the customer depends on how engaged they are with their own consumption.  Some people care a lot, some people will never look at it.  The data is quite valuable to distribution operators, as it assists them when planning expensive network investments.

Re the value/benefits of data vs possible security/privacy concerns ... if we're looking at a highly decentralised energy industry [strongly possible in Australia] then you do need that granularity of data to understand what's happening at various levels in the network.  If it's still strongly centralised, maybe not so much.

In my point of view the entity/organization/company providing the service owns the meter. The power provider needs to ensure the accuracy of all meters so that all customers are billed correctly. If the customer owns the meter, then there is nothing stopping the customer from installing a meter that reports less power usage than actual.

More important questions: Who owns the data? What rights do consumers have and what rights do power utilities have?

Conference Paper A Consumer Bill of Rights for Energy Conservation

I would rather say in whose point of view you would like to see.. 

From customers point of view of having AMI's or Smart meters: This could be stable power supply, energy efficiency, reduced energy bills, low CO2 energy consumption, a feedback of prices etc. These makes the consumer to participate actively in the grid or market trasaction. This is still being criticized what is the consumer doesn't wants or doesn't knows how to use it.

From Aggregators or grid operators or TSO DSOs point of view: A stable real-time demand forecast from utility side, chances to get rid of costly balancing or reserve energies, CO2 emission targets are easy to acheive, Demand response or demand side managment can be implemented, improved services to end customers and finally stable and robust grid status can be acheived.

I would recommend the following book, in case you would like to know more:

http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1119975808.html