Comment 1 for bug 1643974

Have you got any additional information on the circumstances this appeared in, or subsequent occurrences?

As seen in CI testing, in normal operation juju does correctly delete security groups in ec2:

<http://reports.vapour.ws/releases/4648/job/aws-native-deploy-bundle/attempt/690>

However cloud outage and other test problems can result in resource leakage, so we do have a fallback script that goes around deleting old security groups as well.