What we collect from you: FusionKey works without accessing servers other than those associated with the browser itself (Google, and perhaps Mozilla for the Firefox version), and this only for syncing settings across your devices. All sensitive data is encrypted with your Master Key before those servers can see it, though, so they couldn't see the plaintext even if they wanted. We don't have access to this data. There is a link to upload Locks to the PassLok General Directory, which is under our control, so that other users can get them, but Locks are not private and don't allow anyone to decrypt or otherwise see your private data. Posting Locks in the General Directory is entirely optional, too.
What we do with the collected data: The only data of yours we may have access to is your non-private Lock, if you post it in the PassLok General Directory. There it sits, waiting for someone to retrieve it after providing your email address. Otherwise we do absolutely nothing with it. We don't know what Google and Firefox do with your synced data, but they couldn't do much anyway since they'd need your Master Key, which is only inside your head, in order to decrypt it.
What we share with others: only your Lock, if you post it voluntarily in the PassLok General Directory. This is done as a convenience to you since people must have your Lock in order to encrypt data that only you can decrypt. It is also entirely optional (and so far not very popular, either).