Curation and consent. How much is too much?

I’m researching a DCC Legal Watch Paper at the moment, focussing on consent in research (looking at both the legal and the ethical angles). I have been thinking about all this from a curation perspective. With the potential for reuse of resources or data being an important goal in terms of curation, a key question arises which is:

“What use of their data did the participant consent to?”

The answer to this question has a massive bearing on the useability of that data down the line.

So, for example, did the participant consent to:

1. only use A (by researcher A); or
   
2. use A but by any researcher; or
   
3. use A (by researcher A) and use B (by researcher B); or
   
4. researcher A transferring the data to researcher B (crucial if option 3 is to be of any practical use and only researcher A has the data); or
   
5. use of their data by anyone for any purposes.

Of course, some of the answers could be found in the wording of the consent form (N.B. consent is rarely required by law to be in writing but it is still very wise to secure it that way) but my question is about the picture behind it and the legal and ethical appropriateness of what is written in that form – as well as the effectiveness of that consent for enabling scientific progress.

In an era of open approaches to data, the idea of global consent is quite appealing. It ensures that useful data remains useable (IP and contract considerations aside) and ‘open’. But consenting to any use of your personal data...? It has been said that one of the best things about making data open is the things that will be done with it and created by other researchers that you simply would never have thought of. But when it comes to your personal data (i.e. data about you, that identifies you) are you happy to give consent for it to be used in ways you have never imagined? The answer to this may be yes or no, and I would love to hear your thoughts.

Aside from personal feelings on this matter, would such a wide consent be considered legal? Would it be ethical?

What do you think?