A shareholder resolution slated for Omnicom’s June annual meeting calls for it to commission a third-party report to determine whether its advertising policies contribute to civil or human rights violations.

Omnicom manages nearly $40B in client spending.

Sponsored by the Nathan Cummings Foundation, the resolution notes widespread concern that platforms such as Google and Facebook “may be failing to protect civil and human rights by supporting government censorship, facilitating white supremacist activity and enabling voter suppression.”

Omnicom is a member of Facebook’s client council, which advises on issues such as content moderation.

NCF worries that Omnicom “could face reputational and business risk if it is perceived to be contributing to the spread of racism, hate speech” by placing advertising on social media platforms.

It says inadvertent promotion of harmful content by advertisers threatens user safety and brand value.

NCF cites a report that 70 percent of millennials and Gen Xers “will not like, recommend, or purchase a brand whose ads appear next to offensive, hateful or derogatory content."

Laura Campos, director of corporate and political accountability at NCF, said of the resolution: “It’s past time that major advertisers acknowledge the support they give to upholding the hate and disinformation we’ve seen spread on these platforms and act to end it.”

NCF is part of Open MIC (Open Media and Information Companies Initiative), which works with investors to promote openness, equity, privacy and diversity in the media economy.

Open MIC says the Omnicom resolution and a similar one at Home Depot are the first to express concerns about reputational risk connected to advertising on social media platforms.