connection.go | 9 +++++++++

diff --git a/connection.go b/connection.go
index b1ced80084ad657b55446f02931e304340e676c1..3667cf7ad20fa3c98f69020e7645443998724179 100644
--- a/connection.go
+++ b/connection.go
@@ -823,6 +823,15 @@ 			if c.Choked {
 				break
 			}
 			if len(c.PeerRequests) >= maxRequests {
+				// TODO: Should we drop them or Choke them instead?
+				break
+			}
+			if !t.havePiece(msg.Index.Int()) {
+				// This isn't necessarily them screwing up. We can drop pieces
+				// from our storage, and can't communicate this to peers
+				// except by reconnecting.
+				requestsReceivedForMissingPieces.Add(1)
+				err = errors.New("peer requested piece we don't have")
 				break
 			}
 			if c.PeerRequests == nil {