Call it giving in to temptation. Whole Foods Market CEO John Mackey has been caught posting messaging in a Yahoo! chat forum, praising his grocery chain, while heaping abuse on rival Wild Oats Markets.

According to a Reuters News report, Mackey had been using an alias for years to wage his digital smear campaign. 

Mackey used the name "rahodeb," according to court documents filed by the Federal Trade Commission, which cited the forum postings as part of a lawsuit aimed at blocking Whole Foods' planned acquisition of Wild Oats.

The FTC has objected the $565 million acquisition on unfair competition grounds.

Whole Foods confirmed that Mackey had posted the comments under the alias from 1999 to 2006, but insisted that the comments reflected opinions of Mackey, not of the company.