diff --git a/probe/host/tagger_test.go b/probe/host/tagger_test.go
index 6001815e4..ad4582b1d 100644
--- a/probe/host/tagger_test.go
+++ b/probe/host/tagger_test.go
@@ -17,7 +17,7 @@ func TestTagger(t *testing.T) {
 	r := report.MakeReport()
 	r.Process.AddNode(node)
 	rpt, _ := host.NewTagger(hostID).Tag(r)
-	have := rpt.Process.Nodes[endpointNodeID].Copy()
+	have := rpt.Process.Nodes[endpointNodeID]
 
 	// It should now have the host ID
 	wantHostID := report.MakeHostNodeID(hostID)
diff --git a/render/container.go b/render/container.go
index 6b48a758e..440d9fbdc 100644
--- a/render/container.go
+++ b/render/container.go
@@ -191,13 +191,12 @@ func (r containerWithImageNameRenderer) Render(rpt report.Report, dct Decorator)
 		imageNameWithoutVersion := docker.ImageNameWithoutVersion(imageName)
 		imageNodeID := report.MakeContainerImageNodeID(imageNameWithoutVersion)
 
-		output := c.Copy()
-		output = propagateLatest(docker.ImageName, image, output)
-		output = propagateLatest(docker.ImageLabelPrefix+"works.weave.role", image, output)
-		output.Parents = output.Parents.
+		c = propagateLatest(docker.ImageName, image, c)
+		c = propagateLatest(docker.ImageLabelPrefix+"works.weave.role", image, c)
+		c.Parents = c.Parents.
 			Delete(report.ContainerImage).
 			Add(report.ContainerImage, report.MakeStringSet(imageNodeID))
-		outputs[id] = output
+		outputs[id] = c
 	}
 	return outputs
 }
@@ -365,14 +364,13 @@ func MapContainerImage2Name(n report.Node, _ report.Networks) report.Nodes {
 	}
 
 	imageNameWithoutVersion := docker.ImageNameWithoutVersion(imageName)
-	output := n.Copy()
-	output.ID = report.MakeContainerImageNodeID(imageNameWithoutVersion)
+	n.ID = report.MakeContainerImageNodeID(imageNameWithoutVersion)
 
 	if imageID, ok := report.ParseContainerImageNodeID(n.ID); ok {
-		output.Sets = output.Sets.Add(docker.ImageID, report.EmptyStringSet.Add(imageID))
+		n.Sets = n.Sets.Add(docker.ImageID, report.EmptyStringSet.Add(imageID))
 	}
 
-	return report.Nodes{output.ID: output}
+	return report.Nodes{n.ID: n}
 }
 
 // MapContainer2Hostname maps container Nodes to 'hostname' renderabled nodes..
diff --git a/render/detailed/connections.go b/render/detailed/connections.go
index fe1ba57de..576690013 100644
--- a/render/detailed/connections.go
+++ b/render/detailed/connections.go
@@ -75,7 +75,6 @@ func incomingConnectionsSummary(topologyID string, r report.Report, n report.Nod
 		if !node.Adjacency.Contains(n.ID) {
 			continue
 		}
-		remoteNode := node.Copy()
 
 		// Work out what port they are talking to, and count the number of
 		// connections to that port.
@@ -91,7 +90,7 @@ func incomingConnectionsSummary(topologyID string, r report.Report, n report.Nod
 				}
 				key := connection{
 					localNode:  &n,
-					remoteNode: &remoteNode,
+					remoteNode: &node,
 					port:       port,
 				}
 				if isInternetNode(n) {
@@ -127,8 +126,7 @@ func outgoingConnectionsSummary(topologyID string, r report.Report, n report.Nod
 		if !ok {
 			continue
 		}
-		remoteNode := node.Copy()
-		remoteEndpointIDs := endpointChildIDsOf(remoteNode)
+		remoteEndpointIDs := endpointChildIDsOf(node)
 
 		for _, localEndpoint := range localEndpoints {
 			_, localAddr, _, ok := report.ParseEndpointNodeID(localEndpoint.ID)
@@ -143,7 +141,7 @@ func outgoingConnectionsSummary(topologyID string, r report.Report, n report.Nod
 				}
 				key := connection{
 					localNode:  &n,
-					remoteNode: &remoteNode,
+					remoteNode: &node,
 					port:       port,
 				}
 				if isInternetNode(n) {
diff --git a/render/process.go b/render/process.go
index 0d624807d..c756fa2c3 100644
--- a/render/process.go
+++ b/render/process.go
@@ -63,12 +63,11 @@ func (r processWithContainerNameRenderer) Render(rpt report.Report, dct Decorato
 		if !ok {
 			continue
 		}
-		output := p.Copy()
-		output.Latest = output.Latest.Set(docker.ContainerID, timestamp, containerID)
+		p.Latest = p.Latest.Set(docker.ContainerID, timestamp, containerID)
 		if containerName, timestamp, ok := container.Latest.LookupEntry(docker.ContainerName); ok {
-			output.Latest = output.Latest.Set(docker.ContainerName, timestamp, containerName)
+			p.Latest = p.Latest.Set(docker.ContainerName, timestamp, containerName)
 		}
-		outputs[id] = output
+		outputs[id] = p
 	}
 	return outputs
 }
diff --git a/report/node.go b/report/node.go
index b1143f23f..4ff2547f0 100644
--- a/report/node.go
+++ b/report/node.go
@@ -45,16 +45,14 @@ func MakeNodeWith(id string, m map[string]string) Node {
 
 // WithID returns a fresh copy of n, with ID changed.
 func (n Node) WithID(id string) Node {
-	result := n.Copy()
-	result.ID = id
-	return result
+	n.ID = id
+	return n
 }
 
 // WithTopology returns a fresh copy of n, with ID changed.
 func (n Node) WithTopology(topology string) Node {
-	result := n.Copy()
-	result.Topology = topology
-	return result
+	n.Topology = topology
+	return n
 }
 
 // Before is used for sorting nodes by topology and id
@@ -74,121 +72,92 @@ func (n Node) After(other Node) bool {
 
 // WithLatests returns a fresh copy of n, with Metadata m merged in.
 func (n Node) WithLatests(m map[string]string) Node {
-	result := n.Copy()
 	ts := mtime.Now()
 	for k, v := range m {
-		result.Latest = result.Latest.Set(k, ts, v)
+		n.Latest = n.Latest.Set(k, ts, v)
 	}
-	return result
+	return n
 }
 
 // WithLatest produces a new Node with k mapped to v in the Latest metadata.
 func (n Node) WithLatest(k string, ts time.Time, v string) Node {
-	result := n.Copy()
-	result.Latest = result.Latest.Set(k, ts, v)
-	return result
+	n.Latest = n.Latest.Set(k, ts, v)
+	return n
 }
 
 // WithCounters returns a fresh copy of n, with Counters c merged in.
 func (n Node) WithCounters(c map[string]int) Node {
-	result := n.Copy()
-	result.Counters = result.Counters.Merge(Counters{}.fromIntermediate(c))
-	return result
+	n.Counters = n.Counters.Merge(Counters{}.fromIntermediate(c))
+	return n
 }
 
 // WithSet returns a fresh copy of n, with set merged in at key.
 func (n Node) WithSet(key string, set StringSet) Node {
-	result := n.Copy()
-	result.Sets = result.Sets.Add(key, set)
-	return result
+	n.Sets = n.Sets.Add(key, set)
+	return n
 }
 
 // WithSets returns a fresh copy of n, with sets merged in.
 func (n Node) WithSets(sets Sets) Node {
-	result := n.Copy()
-	result.Sets = result.Sets.Merge(sets)
-	return result
+	n.Sets = n.Sets.Merge(sets)
+	return n
 }
 
 // WithMetric returns a fresh copy of n, with metric merged in at key.
 func (n Node) WithMetric(key string, metric Metric) Node {
-	result := n.Copy()
-	result.Metrics[key] = n.Metrics[key].Merge(metric)
-	return result
+	n.Metrics = n.Metrics.Copy()
+	n.Metrics[key] = n.Metrics[key].Merge(metric)
+	return n
 }
 
 // WithMetrics returns a fresh copy of n, with metrics merged in.
 func (n Node) WithMetrics(metrics Metrics) Node {
-	result := n.Copy()
-	result.Metrics = result.Metrics.Merge(metrics)
-	return result
+	n.Metrics = n.Metrics.Merge(metrics)
+	return n
 }
 
 // WithAdjacent returns a fresh copy of n, with 'a' added to Adjacency
 func (n Node) WithAdjacent(a ...string) Node {
-	result := n.Copy()
-	result.Adjacency = result.Adjacency.Add(a...)
-	return result
+	n.Adjacency = n.Adjacency.Add(a...)
+	return n
 }
 
 // WithEdge returns a fresh copy of n, with 'dst' added to Adjacency and md
 // added to EdgeMetadata.
 func (n Node) WithEdge(dst string, md EdgeMetadata) Node {
-	result := n.Copy()
-	result.Adjacency = result.Adjacency.Add(dst)
-	result.Edges = result.Edges.Add(dst, md)
-	return result
+	n.Adjacency = n.Adjacency.Add(dst)
+	n.Edges = n.Edges.Add(dst, md)
+	return n
 }
 
 // WithControls returns a fresh copy of n, with cs added to Controls.
 func (n Node) WithControls(cs ...string) Node {
-	result := n.Copy()
-	result.Controls = result.Controls.Add(cs...)
-	return result
+	n.Controls = n.Controls.Add(cs...)
+	return n
 }
 
 // WithParents returns a fresh copy of n, with sets merged in.
 func (n Node) WithParents(parents Sets) Node {
-	result := n.Copy()
-	result.Parents = result.Parents.Merge(parents)
-	return result
+	n.Parents = n.Parents.Merge(parents)
+	return n
 }
 
 // PruneParents returns a fresh copy of n, without any parents.
 func (n Node) PruneParents() Node {
-	result := n.Copy()
-	result.Parents = EmptySets
-	return result
+	n.Parents = EmptySets
+	return n
 }
 
 // WithChildren returns a fresh copy of n, with children merged in.
 func (n Node) WithChildren(children NodeSet) Node {
-	result := n.Copy()
-	result.Children = result.Children.Merge(children)
-	return result
+	n.Children = n.Children.Merge(children)
+	return n
 }
 
 // WithChild returns a fresh copy of n, with one child merged in.
 func (n Node) WithChild(child Node) Node {
-	result := n.Copy()
-	result.Children = result.Children.Merge(MakeNodeSet(child))
-	return result
-}
-
-// Copy returns a value copy of the Node.
-func (n Node) Copy() Node {
-	cp := MakeNode(n.ID)
-	cp.Topology = n.Topology
-	cp.Counters = n.Counters.Copy()
-	cp.Sets = n.Sets.Copy()
-	cp.Adjacency = n.Adjacency.Copy()
-	cp.Edges = n.Edges.Copy()
-	cp.Controls = n.Controls.Copy()
-	cp.Latest = n.Latest.Copy()
-	cp.Metrics = n.Metrics.Copy()
-	cp.Parents = n.Parents.Copy()
-	cp.Children = n.Children.Copy()
-	return cp
+	n.Children = n.Children.Merge(MakeNodeSet(child))
+	return n
 }
 
 // Merge mergses the individual components of a node and returns a
diff --git a/report/topology.go b/report/topology.go
index f64be7122..1beba4f79 100644
--- a/report/topology.go
+++ b/report/topology.go
@@ -167,7 +167,7 @@ type Nodes map[string]Node
 func (n Nodes) Copy() Nodes {
 	cp := make(Nodes, len(n))
 	for k, v := range n {
-		cp[k] = v.Copy()
+		cp[k] = v
 	}
 	return cp
 }