Probably there is no straight answer. The ownership of data depends on the permission of the person whose data is under question to the IT company or whosoever else wishing to handle or use it. However, unless copyrighted, all data are perhaps free to all.
"Data ownership is the act of having legal rights and complete control over a single piece or set of data elements. It defines and provides information about the rightful owner of data assets and the acquisition, use and distribution policy implemented by the data owner." (www.techopedia.com)
In current days the former "black gold", which was petrol prospection, turned out to be data. But data collection, despite the statement of agreement or not agreement of each person, is deeply replated with the ethics of each company as it was clearly perceived with the Facebook scandal. World societies are migrating to a new era of super development, contrasting with everything that humankind has ever experienced before. Once again, much more than the need for thorough legislation, which regulates what to do and not to do, is the need for internal ethical in each company to prevent usage of data to unallowed commercial purpose. The owners of our data are a small number of gigantic enterprises that can pay for any economical sanction brought against them but despite the sanction the damages are also done.
The real owner of the data used by the World Bank, UNESCO, the International Fund, and UNCTAD and other international organizations is the countries itself of the world, because each country has a center to collect data on the various activities (national accounts, education and other activities) that it publishes, and gave an official copy or copies to the mentioned international institution.
These data are called by researcher a raw data, but as soon as the researcher collects them, classifies and makes some changes to them or derives new data, it becomes his property, he can share it or participate it according to his decision.
It is hard to find correct answer for answering the owner of data. It all depend on the specific situation like you mention the case of World Bank. What I still have an unanswered question is who is the owner of my data related with my name, email account, or related. We usually click agree button when we create an account but how many of us read each line to understand what we are asked to agree? I personally try to read the main point but still have to pay attention anything we are agreeing when we create an account in any application or web. What are your thoughts?
Data ownership should follow the question: how it was created and who created it. if a soft ware programming was used to create it, then I guess it follows the company that owns the software & Vise versa. However, I think this is one of the most difficult questions that we can face during our research work.. I'm interested to see where the discussion would take us.