Updating SM-ONOS copyright and adding note

Change-Id: I95a533e99a883c29e3f470418db337e690babad2

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.onosproject.security.impl;
 
 

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.onosproject.security.impl;
 
 import com.google.common.collect.Lists;
@@ -43,10 +58,11 @@ import org.slf4j.Logger;
 
 import static org.slf4j.LoggerFactory.getLogger;
 
-
-
 /**
  * Security-Mode ONOS management implementation.
+ *
+ * Note: Activating Security-Mode ONOS has significant performance implications in Drake.
+ *       See the wiki for instructions on how to activate it.
  */
 
 @Component(immediate = true)