I have used Ning only briefly a couple of times. I haven't set up a site on it. What if they want to leave, the customers, can they just grab their data and go

I have used Ning only briefly a couple of times. I haven't set up a site on it. What if they want to leave, the customers, can they just grab their data and go somewhere else? To another social network like Facebook or MySpace or somewhere like that? LinkedIn?