Who Owns Student Work?

Our district will be moving to a new web portal service next year. One of the features mentioned is students will be able to create accounts so they can have access to blogging and wiki tools. Sounds like a great idea right? Not so fast.

I found out our new system does not have an export feature to allow students to move content they created to other resources. This could be a problems because we usually have a lot of student turnover due to being a military and service-based community. If a student leaves the district, their work done on the district site will be deleted at some point. 

Does this mean students do not have rights to digital work created for school assignments? This question came up in a conversation I had with a Librarian who worked in a college. She told me that colleges could claim ownership of student work. This was shocking news to me. Again I ask, do K-12 students have a right to their work online? Please give me your thoughts on this subject, especially those participating in the Beaufort County Summer Institute Digital Portfolio session.