This means Microsoft can use photos, documents, emails, and other files you store on OneDrive or other services for purposes beyond just storing them, which raises privacy and intellectual property concerns.
Microsoft's Services Agreement governs all major consumer Microsoft products and contains provisions that materially limit consumer rights, including mandatory arbitration and a class action waiver for US users, a broad content license that allows Microsoft to use anything you post or store, and a unilateral right to suspend or terminate accounts with limited notice. Consumers face significant data exposure through Microsoft's broad collection and use practices across services, and limited financial recourse given liability caps set at the amount paid in the prior 12 months. You can opt out of arbitration by mailing written notice to Microsoft Corporation, One Microsoft Way, Redmond, WA 98052 within 30 days of first accepting the agreement.