diff --git a/Lidgren.Network/NetPeer.Internal.cs b/Lidgren.Network/NetPeer.Internal.cs
index 857131c..22e60d5 100644
--- a/Lidgren.Network/NetPeer.Internal.cs
+++ b/Lidgren.Network/NetPeer.Internal.cs
@@ -50,6 +50,8 @@ namespace Lidgren.Network
 
 		private void InitializeNetwork()
 		{
+			VerifyNetworkThread();
+
 			lock (m_initializeLock)
 			{
 				m_configuration.Lock();
diff --git a/Lidgren.Network/NetPeer.cs b/Lidgren.Network/NetPeer.cs
index 7c7ba69..1bedc4c 100644
--- a/Lidgren.Network/NetPeer.cs
+++ b/Lidgren.Network/NetPeer.cs
@@ -13,6 +13,7 @@ namespace Lidgren.Network
 		private static int s_initializedPeersCount;
 
 		private int m_listenPort;
+		private object m_tag;
 
 		internal readonly List<NetConnection> m_connections;
 		private readonly Dictionary<IPEndPoint, NetConnection> m_connectionLookup;
@@ -42,6 +43,15 @@ namespace Lidgren.Network
 		/// </summary>
 		public int Port { get { return m_listenPort; } }
 
+		/// <summary>
+		/// Gets or sets the application defined object containing data about the peer
+		/// </summary>
+		public object Tag
+		{
+			get { return m_tag; }
+			set { m_tag = value; }
+		}
+
 		/// <summary>
 		/// Gets a copy of the list of connections
 		/// </summary>