Sorry, I could have made my original comment clearer. I don't think there were any other IP addresses accessed. The "other industries" that were involved were

Sorry, I could have made my original comment clearer. I don't think there were any other IP addresses accessed. The "other industries" that were involved were using Google Apps, so Google has access to those records. That's why they have to inform the other companies their security was breached: the traffic did go through Google so they're the only ones who know about it.