A Harvard professor claims that some of Google's ads discriminate, linking "racially associated" names to a possible criminal background.
She found that names associated with black people were more likely to show ads suggesting arrest, as compared to "white identifying" names.
Names associated with black people, such as DeShawn, Darnell and Jermaine netted criminal ads in 81 to 86 percent of searches on one site, and up to 95 percent on the other.
However Geoffrey, Jill and Emma, more typically associated with white people, resulted in these types of ads 23 to 29 percent of the time on one site and zero to 60 percent on the other, Sweeney's study claimed.
If you did a search on "Latonya Evans" you were more likely to see "Latonya Evans, Arrested?" while the name Laurie Ryan gave a benign result of "Background of Laurie Ryan".
Google insists that it does not conduct racial profiling in AdWords.
In a statement to ABC News, Google said that it had a policy which forbids ads that advocate against an organisation, person or group of people. It is up to individual advertisers to decide which keywords they want to choose to trigger their ads.
Sweeney claims that more research is needed and suggests possible blame on Google's algorithms and financial interests with advertisers.