The Electronic Frontier Foundation  reports:

Facebook subsidiary Instagram recently revised their terms of service, adding controversial new terms that will allow the company to monetize your photos. Instagram recently responded to the public outcry, and we hope their upcoming language changes reflect the three key principles we developed for social networking services: informed decision making, control, and the right to leave.

The article goes on to explain in more detail that things you consider private, could end up being used commercially. Even if you close your account, your picture, or pictures that you post could still be circulated in advertisements or other online/offline content.

 Currently users of the service are voicing their concerns and the company may reconsider the language of the new terms of agreement.