Database connection multi users

Dear people,

Difficult level : High.

I’m running a multi site – with 6 subsites. People can join every site and upload photos. If they join 1 site (or the main site) they have automatically acces to al the 6 sites to upload fotos. (using plugin Easy digital download)

This works perfect, the only thing, if they want to show their photo the have: site1.mainsite.com/name. But there are only the photos of the first site: So the photos of the seconden site URL : site2.mainsite.com/name.

So if they want to make publicity for themselves they need to choose. Because they are 1 user thats have acces to all the sites. I’m wondering is it possible to connect or all sites. So they have URL: http://www.mainsite.com/name (witch would show all their photos) or connect it directly to their database.

Does someone ever thought about this?

Kind regards
Dylan