CHANGE: Google Co-Founders Page, Brin Give Up Management Roles.

Although still closely identified with the company, the co-founders have been a dwindling visible presence inside the Mountain View, Calif., campus for years, current and former employees say.

Google faces an unusually fierce collection of threats this year. Competitors like Amazon.com Inc. are chipping at its online-advertising business, while state and federal regulators are beginning broad investigations of purported anticompetitive behavior. Google has pledged to cooperate with the inquiries.

“While it has been a tremendous privilege to be deeply involved in the day-to-day management of the company for so long, we believe it’s time to assume the role of proud parents,” Messrs. Page and Brin wrote in the letter. “We plan to continue talking with Sundar regularly, especially on topics we’re passionate about.”

Maybe we could mark the occasion than with an antitrust investigation.