Unencrypted SNS topic.
Explanation
Queues should be encrypted with customer managed KMS keys and not default AWS managed keys, in order to allow granular control over access to specific queues.
Insecure Example
The following example will fail the AWS016 check.
resource "aws_sns_topic" "my-topic" {
# no key id specified
}
Secure Example
The following example will pass the AWS016 check.
resource "aws_sns_topic" "my-topic" {
kms_master_key_id = "/blah"
}