At the UK Data Archive we work with hundreds of social researchers every year to ensure that primary data they create from research grants can be shared with other researchers. ESRC and NERC award holders must offer all data for sharing, and increasingly most funders now have data sharing policies.
Some reseachers and some ethics committees feel there is a real tension between data sharing and data protection, but the fact is that there is often great misunderstanding about what are personal, sensitive and confidential data. Most data collected by reseachers are neither personal, sensitive or confidential, as defined by the Data Protection Act. See http://www.data-archive.ac.uk/sharing/define.asp .
We are currently working with Research Ethics Committees across the UK to discuss with them how data can be shared and under what conditions. We would be interested to hear your views or experiences.