The second in a series of monthly reports on top advertising networks that support illegal download sites was missing a notable name: Google. Whether or not this drop-off means anything has yet to be seen.

The tech giant’s advertising network ranked second in the first Ad Network Piracy Report, which tracked the source of advertisements funding top infringing sites on the Google Transparency Report. OpenX, another large advertising network, also fell out of the Top 10. The Annenberg Innovation Lab says both companies “have drastically reduced the number of infringing sites they are placing ads on.”

Google’s disappearance from the Top 10 list comes after the company’s role in funding pirate sites received some mainstream media coverage. But some articles last month painted an unclear picture on Google’s role. A company spokesperson told the Los Angeles Times the study was “mistaken” to suggest the company’s ads were a “major source of funds” for illegal download sites; the nature of online advertising makes it difficult to determine guilt. RIAA CEO Cary Sherman told the New York Times “[t]he ecosystem for online ads is incredibly complicated.”

Admxr, Mgid and Adtransfer were new additions to Annenberg Labs’ second Top 10. Annenberg Lab notes that Adtranfers “does not even have a website” and appears to be “exclusively in the pirate advertising business.” Yahoo’s Right Media ad exchange was third this time, after coming in sixth on the initial Top 10.

The report again listed a sample of brands whose advertisements appeared on “multiple occasions.” Amazon, American Express, Converse, K Swiss, Nissan, Nokia, Samsung, Toyota, Verizon and Walt Disney World are among the brands listed. [Billboard.biz]