After testing Google’s algorithm and conducting over 100 interviews, the Journal reported that Google has intervened in its algorithm to demote spam sites and maintain blacklists as well as make changes to its algorithm that favored the search ranking of a major advertiser, eBay, contrary to its public position.

The report could add fuel to conservatives’ claims of bias and censorship by Google based on how it determines what content surfaces in its search engine and on its video platform, YouTube.

Related: WSJ report about Google search manipulation gets a lot wrong