There were reports in the forums about subdomain data being visible. We had set our quantcast account to keep subdomain hidden for public consumption, but a bug on their end exposed it. To remedy the situation we reached out the QC, and temporarily hid all QC data while it was fixed.
Today it was fixed. Subdomain data is private, but you can see information for the overall HubPages acct.
Quantcast examined the affinities* of online banking customers to understand where else they go on the Web. This unique capability helps advertisers extend their reach beyond the largest, least-differentiated sites to “long tail” websites that are harder to identify, but richer in the target audiences.