The data protection commissioner of the German federal state of Schleswig-Holstein has come out against Google's proposed $3.1 billion acquisition of DoubleClick.
Such a merger would "lead to a massive violation of data privacy rights" for consumers in the European Union if the databases of the two companies were combined, says Thilo Weichert, data protection commissioner for Germany's northernmost state.
In a letter to the European Commissioner for Competition, Weichert writes that search engines in general already violate consumer rights to "informational self-determination" by retaining data for so long, among other things.
A Google spokesman provided this statement: "We believe that this acquisition will increase competition and benefit both consumers and advertisers, and that it will ultimately be approved by government regulators."
In response to concerns that the companies will combine their databases, Google and DoubleClick have pointed out that DoubleClick does not own, and has limitations on its use of, the data it processes for its publisher and advertiser clients.
In addition, the European Consumers' Organization has lodged a complaint with the European Competition Commissioner, arguing that the merger would lead to a monopoly in the online advertising market, and Yahoo is challenging it there as well.
Some privacy groups in the U.S. oppose the Google-DoubleClick merger, and Microsoft testified at a U.S. Senate hearing last week that a Google-DoubleClick merger would be anticompetitive.