Hi Mika,
Actually, that wasn’t my question, but thanks for attempting an answer.
What I am asking is this: there are clearly two different approaches to securing oEmbed, the whitelist approach (which wordpress uses) and the iframe approach (as detailed on the oEmbed.com site). Why has WordPress chosen the former?
From my limited understanding, it seems a weaker solution to me as it requires the maintenance of the whitelist, but I expect I am missing something.
thanks,
Rob