I'm working on getting User Synchronization working for our SharePoint 2010 deployment and after fighting with it for a while (and the almost black magic that was associated with it) I got it to start working last night.
This morning I found several odd entries in the "My Newsfeed" page they were all in the format:
Username added 10 new colleagues. 6:00 PM Random User 1, Random User 2, Actual Colleague 1, Random User 3, Actual Colleague 2 ...
I even had one of these on the "My Profile" page that had my boss and a coworker and five random service accounts.
The users who have managers listed in AD have correct associations but I'm at a complete loss on how some of these news items are being created.
Update
I started looking around more and my boss has random employees in his feed in addition to the service accounts. Other than the fact they are all members of domain users, I'm not sure where the link is.