U.S. authorities investigating Alphabet Inc.’s Google for anti-competitive behavior have recently begun probing the company’s $116 billion-a-year advertising business.

Attorneys general for 50 U.S. states and territories along with the U.S. Department of Justice appear to be acting on accusations from rivals, lawmakers and consumer advocacy groups that the biggest seller of online ads engages in unfair tactics. Google disputes its dominance

“Ad tech is a very crowded field, and Google competes with hundreds of companies, including household names like Adobe, Amazon, AT&T, Comcast, News Corp, and Verizon,” company spokesman Josh Zeitz said. “Publishers and advertisers mix and match technology partners to meet their different needs, creating both competition and innovation.”

The five common concerns about Google raised by 10 ad industry executives are Search & YouTube, Acquisitions, Bundling, Last Look, and Chrome.

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