SAN FRANCISCO (MarketWatch) - Google Inc. GOOG, -2.37% used sensitive personal information to target health-related ads at users, in violation of privacy law in Canada, a Canadian privacy watchdog said Wednesday. The agency said its investigation was triggered by a complaint from a man with sleep apnea, who said he was "followed" by ads for devices geared to treating the condition after conducting online searches on the illness. "As Canadians spend more and more time online, they create a digital trail that can reveal a great deal about a person," the agency's interim privacy commissioner Chantal Bernier said in a statement. "Organizations such as Google must ensure privacy rights are respected in this complex environment." Google has agreed to "take steps aimed at stopping the privacy-intrusive ads," the agency said. A spokesperson for Google Canada told MarketWatch, "We've worked closely with the Office of the privacy commissioner throughout this process and are pleased to be resolving this issue." Google shares were down 0.1% in Wednesday trades.