High ranking sites drop following Google update

It seems there are some high ranking websites that overnight have seen their ranking reduced. They are therefore not showing their website on that all important first page of search results. The reason is Googles latest update "Panda". Scott Huffman, head of search evaluation at Google , said it was "almost absurd" to suggest that the results were rigged. Search algorithms are regularly changed that influence search results. So why the fuss? Well one site is ciao.co.uk and is owned by Microsoft who just happened to be leading an EU competition agaimst Google. Its visability actually fell by 94%! These updates are often made to weed out content farms. However I have never heard of such a drastic loss of rank for such a site as ciao. The ranking loss is enough to put a site out of business!