Fears that Instagram photos will be used in brand marketing will be realized Wednesday when social-media-management company Venueseen opens its application programming interface (API) for an Indy 500 marketing campaign.

The move will afford brands the ability to take user-uploaded Instagram photos and use them in a variety of marketing channels without user consent.

"The C-suite doesn't care about likes and comments; they want to see how social content can be monetized," Venuessen CEO Brian Zuercher said in a statement. "Now, [brands] can 'unlock' amazing Instagram photos and showcase them on their own websites or other campaign channels."

For this specific campaign, the Indianapolis Motor Speedway plans to use geotags to plot Instagram photos with the #Indy500orBust hashtag on an interactive map. Fans can also win a VIP race experience by posting their photos on Instagram, Mr. Zuercher said.

Jarrod Krisiloff, marketing director for the Indy 500, said that user-uploaded photos will only appear in Indy500orBust.com, the microsite associated with the campaign hashtag.

"When someone hashtags [an Instagram photo], we're not using them commercially, we're just showing them. People are making the choice," Mr. Krisiloff said.

The Indy 500 received advanced access to Venueseen's API for its campaign, but the API will be available to any interested brands come Wednesday. In addition to allowing brands to see specific Instagram photos, Venuessen's software provides access to geotagged Foursquare photos.

By providing an API, Venueseen is opening up a seemingly endless realm of possibilities for how brands can legally use Instagram photos unbeknownst to the users. As Mr. Zuercher said in an interview, Instagram photos have always been public domain and brands have always had the liberty to use them as they see fit. This new software feature merely simplifies the process.

But it also exposes Venueseen and its marketing customers to ridicule from Instagram users who have stated they don't want their Instagram photos used for marketing purposes. When Instagram changed its terms of service last month, users were so unhappy with the prospect of their photos being sold and used by advertisers that Instagram reverted to its old terms of service less than 24 hours after the change.

Those old terms of service don't provide users with much protection either, though. Instagram users have always surrendered the licensing rights to their content in exchange for using the free service.

Mr. Zuercher said that a user backlash will be avoided if brands communicate with Instagram users about how they intend to use their photos.

"We end up helping that concern for consumers," he said. "People want to be participating in a good way with the products and services that are behind them. What they don't want is to feel like someone is stealing."