Actually, it pops up an iframe to WordPress.com, to save site owners from having to juggle their own oauth keys and connection, then it syncs the comment back d

Actually, it pops up an iframe to WordPress.com, to save site owners from having to juggle their own oauth keys and connection, then it syncs the comment back down to your local installation. So you always own your own data, and can deactivate the module without losing anything.