AWS terms do not grant them a license or ownership over your data, although "If you process the personal data of End Users or other identifiable individuals in your use of a Service, you are responsible for providing legally adequate privacy notices and obtaining necessary consents for the processing of such data" - so if you just store random files on s3 or EBS it's not like AWS can do anything they want with it.
The GDPR DPA does a good job of encompassing the entire extent of their data use:
> AWS will not access or use, or disclose to any third party, any
Customer Data, except, in each case, as necessary to maintain or provide the Services, or as
necessary to comply with the law or a valid and binding order of a governmental body (such as a
subpoena or court order)...
https://aws.amazon.com/service-terms/
The GDPR DPA does a good job of encompassing the entire extent of their data use:
> AWS will not access or use, or disclose to any third party, any Customer Data, except, in each case, as necessary to maintain or provide the Services, or as necessary to comply with the law or a valid and binding order of a governmental body (such as a subpoena or court order)...
https://d1.awsstatic.com/legal/aws-gdpr/AWS_GDPR_DPA.pdf