It says in the article that their IP space is from a legacy block, which means it's has never been given by IANA to any RIR, so ARIN can't make a claim on it. Not sure how they'd get 666k addresses out of legacy space though :).
They specifically allow it now, and I don't think this article has to do with 47/8. They probably cannot transfer 47/8. There are other, smaller allocations in ARIN WHOIS; my officemate rattled them off out loud but I couldn't add in my head fast enough. Dig through WHOIS, it probably adds up to 666k.
