just some thoughts about the rest of the translation based on text frequently found when signing up for free online accounts, G-Mail, Yahoo, Facebook, etc.
"X" will not share / distribute / release any client data with any third party (service? company?, etc.).in any given case without the client's explicit consent.
If a client decides not to share their data in any such case, they can, of course, refuse (deny) that such a connection is made." (The last bit needs clarification, Zustimmung?)
"...they can always refuse / deny / reject / object to "X" divulging / sharing / releasing / distributing such data..." maybe?
Anyhow, just some thoughts......