It needs to be said that one of the original value propositions to flickr was their API and famous "you show me yours, i'll show you mine" policy -- basically letting users take all their photos and data, including porting them to any service that also allowed full export.

This includes full resolution, EXIF data, etc. (though it did/does not AFAIK include comments inside the community, which are subject to user TOS with other users, thus this makes sense in several ways)