Commonwealth Bank of Australia, Coca-Cola, Optus, Woolworths and the Australian government have joined a global line-up of high-profile brands to freeze their advertising deals with YouTube after the Google-owned video site was found to be facilitating soft-core paedophilia rings in comment threads. The Australian Financial Review can reveal at least two of the largest media buying groups here, IPG Mediabrands and Dentsu Aegis Network, have placed a blanket trading halt on YouTube until more details emerge. This means a whole host of major Australian brands will not be appearing on the video platform. North American advertisers such as Nestle, AT&T and Disney have halted all their advertising on YouTube in recent days.