By default, maven-s3-wagon set the ACL to publicRead. This isn't desired behaviors if you happen to be using private S3 buckets
If you don't explicitly set a default, the ACL is automatically set depending on the bucket's ACL (this is the desired behaviour for working with ACL). This means if you don't specify an ACL in settings.xml, you shouldn't even be making the request.setCannedAcl call
Setting the default to publicRead means you get permission errors if you are trying to use maven-s3-wagon unless you explicitly give the required permission to the S3 user
Setting the default ACL to publicRead also makes no sense for a private repository (repository is private for a reason!)
By default, maven-s3-wagon set the ACL to publicRead. This isn't desired behaviors if you happen to be using private S3 buckets
settings.xml, you shouldn't even be making therequest.setCannedAclcall