A Bloomberg News investigation into the fact that the campaigns of Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.) buy things from Amazon , and how those purchases are allegedly at odds with the candidates crusades against the corporate giant, violates a company editorial policy adopted after the news outlets founder, former New York City Mayor Michael Bloomberg , entered the presidential race in November.

Since Bloomberg remains owner of Bloomberg News, the companys editor-in-chief John Micklethwait improvised an editorial policy designed to escape accusations of bias in favor of its founder and owner.

Writing to Bloomberg News staff, Micklethwait said in a late November memo that the news site would continue to cover the 2020 presidential campaign in much the same way as we have done so far.

But, Micklethwait clarified, the outlet will also maintain its tradition of not investigating Bloomberg, his family or his foundation, and that, in the interest of fairness, it would extend the same policy to his rivals in the Democratic primaries.

On Monday, however, Bloomberg News published just such an investigation of Bloombergs rivals: Sanders, Warren Campaigns Spend the Most On Amazon While Trashing It.