An Amazon Appstore ad service that lets you use an Amazon app to display ads to customers is being used by a Chinese ad company that has been accused of manipulating data from Amazon’s cloud to target ad impressions, according to a report published Tuesday by the Washington Post.

The app, called Amazon Cloud Advertising, has been used by an advertising firm in Beijing and other cities for years to distribute targeted ads, the report said.

The Beijing-based advertising company was also reportedly able to buy ads from other ad networks through the service and share data with other ad vendors, the Post said.

Advertising firms have been criticized for using Amazon’s service to target users and target advertising based on their location.

Some have said the company has overstepped its authority and used its cloud-based services to collect data from advertisers and sell it to other companies, including rivals.

The app is also used by other ad agencies in the U.S. to deliver ads to users, but the company said the app is not a direct competitor to Amazon’s Cloud Advertising.

The Washington Post report was based on public records and interviews with people who said they had used the app to deliver targeted ads.

The Post said the Beijing-listed Beijing Chengdu Advertising Group also uses the app.

It said the ads it posted on the app were targeted at Chinese and U.K. consumers, and that the company used the Amazon app store to deliver the ads.

A spokesman for Amazon didn’t immediately respond to a request for comment.

The App Store has become a major player in the online advertising market.

The company has built out a large inventory of apps to support its massive catalog of titles, and Amazon has launched several cloud services, including Amazon Cloud Drive and Amazon Web Services, which are designed to allow customers to share data and manage their computing.