Azure ARM orphaned networks not cleaned up when node deleted which also prevents the resource group from being removed.
Not sure this is actually a bug.
According to https://github.com/duncangrant/jclouds-labs/blob/dbadb279f14848f21879f7eb6c7136e1a5f11192/azurecompute-arm/src/main/java/org/jclouds/azurecompute/arm/compute/strategy/CleanupResources.java#L94-L95 the network should be cleaned up when the resource group is deleted.
However this is not the case. As can be seen here: https://github.com/duncangrant/jclouds-labs/blob/dbadb279f14848f21879f7eb6c7136e1a5f11192/azurecompute-arm/src/main/java/org/jclouds/azurecompute/arm/compute/strategy/CleanupResources.java#L207
As the resource group contains the network this will prevent the resource group from being deleted leaving both the network and the resource group.
I think that, assuming the network was created by jclouds at the same time as the resource group, it is reasonable to delete both here.