I recently started working for a new company and they have a lot of white label sites. Just last week I checked Google Webmaster Tools for one of our bigger in-house white label sites (one we personally run) and discovered that Google removed it from the index, though we never got a message in Webmaster Tools. I also performed a site:operator search just to be sure and it definitely isn't listed anymore.
Finding out a little bit more about the site, I discovered it was changed to pretty much be an exact match of our main site and that it used to have canonical tags but they were removed. Not sure why.
I don't have a lot of experience with white labels, so I guess this is more of a general help question, though I was specifically wondering if putting back the canonical tags that were previously removed would be enough.