Since the early hours of May 25, ad exchanges have seen European ad demand volumes plummet between 25 and 40 percent in some cases, according to sources. Ad tech vendors scrambled to inform clients that they predict steep drops in demand coming through their platforms from Google. Some U.S. publishers have halted all programmatic ads on their European sites. Google contacted DoubleClick Bid Manager clients over the last few days to warn them that until it has completed its integration into the Interactive Advertising Bureau Europe and IAB Tech Lab’s GDPR Transparency & Consent Framework that publishers, ad tech vendor partners and advertisers should expect a “short-term disruption” in the delivery of their DoubleClick Bid Manager campaigns on third-party European inventory, starting May 25. The frustration for many has been directed at Google. The day before the deadline, buyers were warned also to not buy any inventory via Google on third-party exchanges, especially those using tracking and ad-verification pixels, as Google couldn’t verify whether those partners were compliant or not, according to sources. Some agency groups were alerted to this late on May 24, while others felt Google’s guidance had been nonexistent, according to agency sources.