LegitScript.com reported that 89.7% of pharmaceutical category ads on Bing’s adCenter were from illegal pharmecies. Microsoft responded stating that the number of illegal ads was far lower than reported by LegitScript but admitted to the violations.

Microsoft adCenter has taken a number of security steps since to remove the bad entries, inlcuding: manually reviewing pharma-related keywords, investigating reports of hijacked and misused landing pages, documenting the process of how the illegal advertisers use the Bing/Microsoft ad system.