These notifications are from executives registered with 'Not Actively Looking' (a sister site of ours), who have seen your firm on the NAL website and have decided to connect with your firm. They are just an extra person in your database that might turn up when you do a search - you don't have to do anything with them and they can't see any of your information. All users can disable the notifications about these connections in the settings page (towards the bottom of the page) if they prefer not to see them.
Your firm's administrators can also elect to disable NAL connections completely for the entire firm, in which case there will be no more notifications, but also the additional pool of NAL candidates will also not appear in searches any more. The administrator should contact us if they decide to do that, and we will arrange it.