diff --git a/htroot/ConfigBasic.html b/htroot/ConfigBasic.html
index e8bd56d11..bef5b4775 100644
--- a/htroot/ConfigBasic.html
+++ b/htroot/ConfigBasic.html
@@ -53,6 +53,14 @@
 	<li>
           <img src="env/grafics/ok.png" height="16" width="16" alt="ok" />&nbsp;Use Case: what do you want to do with YaCy:<br />
           <fieldset>
+          #(switchError)#::<div class="alert alert-danger" role="alert"><p>Can not leave from Intranet Indexing : one or more remote Solr instances are attached and may contain private documents indexed.</p> 
+          <p>Please first delete all index entries (see the <a href="IndexControlURLs_p.html">URL Database Administration</a> page) or disconnect the remote Solr instance(s) from YaCy (see the <a href="IndexFederated_p.html">Index Sources &amp; Targets</a> page).</p></div>
+          #(/switchError)#
+          #(switchWarning)#::<div class="alert alert-warning" role="alert"><p>One or more remote Solr instances are attached and may contain indexed public documents irrelevant to your local domain.</p> 
+          <p>You may want to delete all indexed documents (see the <a href="IndexControlURLs_p.html">URL Database Administration</a> page), disconnect or change the remote Solr instance(s) attached (see the <a href="IndexFederated_p.html">Index Sources &amp; Targets</a> page).</p></div>
+          ::<div class="alert alert-warning" role="alert"><p>One or more remote Solr instances are attached.</p> 
+          <p>Please be sure you want to expose the indexed documents in this new mode. You may want to disconnect or change the remote Solr instance(s) attached (see the <a href="IndexFederated_p.html">Index Sources &amp; Targets</a> page).</p></div>
+          #(/switchWarning)#
           <table border="0">
           <tr>
             <td style="width: 256px;"><input type="radio" name="usecase" value="freeworld" id="usecaseFreeworld" #(freeworldChecked)#::checked="checked"#(/freeworldChecked)# /><label for="usecaseFreeworld">Community-based web search</label></td>
diff --git a/htroot/ConfigBasic.java b/htroot/ConfigBasic.java
index 414a47908..2eb239c32 100644
--- a/htroot/ConfigBasic.java
+++ b/htroot/ConfigBasic.java
@@ -171,33 +171,60 @@ public class ConfigBasic {
         }
 
         // set a use case
+        prop.put("setUseCase_switchError", 0);
+        prop.put("setUseCase_switchWarning", 0);
         String networkName = sb.getConfig(SwitchboardConstants.NETWORK_NAME, "");
         if (post != null && post.containsKey("usecase")) {
+			boolean hasNonEmptyRemoteSolr = sb.index.fulltext().connectedRemoteSolr()
+					&& (sb.index.fulltext().collectionSize() > 0 || sb.index.fulltext().webgraphSize() > 0);
             if ("freeworld".equals(post.get("usecase", "")) && !"freeworld".equals(networkName)) {
-                // switch to freeworld network
-                sb.setConfig(SwitchboardConstants.CORE_SERVICE_RWI, true);
-                sb.switchNetwork("defaults/yacy.network.freeworld.unit");
-                // switch to p2p mode
-                sb.setConfig(SwitchboardConstants.INDEX_DIST_ALLOW, true);
-                sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW, true);
-                sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW_SEARCH, true);
-                // set default behavior for search verification
-                sb.setConfig(SwitchboardConstants.SEARCH_VERIFY, "iffresh"); // nocache,iffresh,ifexist,cacheonly,false
-                sb.setConfig(SwitchboardConstants.SEARCH_VERIFY_DELETE, "true");
+            	if("intranet".equals(networkName) && hasNonEmptyRemoteSolr) {
+            		/* One or more non empty remote Solr(s) attached : disallow switching from intranet to another network to prevent disclosure of indexed private documents */
+            		prop.put("setUseCase_switchError", 1);
+            	} else {
+                	if(hasNonEmptyRemoteSolr) {
+                		/* One or more non empty remote Solr(s) attached : warn the user even if not coming from intranet as indexed documents may be irrelevant for the new mode */
+                		prop.put("setUseCase_switchWarning", 2);
+                	} 
+            		// switch to freeworld network
+            		sb.setConfig(SwitchboardConstants.CORE_SERVICE_RWI, true);
+            		sb.switchNetwork("defaults/yacy.network.freeworld.unit");
+            		// switch to p2p mode
+            		sb.setConfig(SwitchboardConstants.INDEX_DIST_ALLOW, true);
+            		sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW, true);
+            		sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW_SEARCH, true);
+            		// set default behavior for search verification
+            		sb.setConfig(SwitchboardConstants.SEARCH_VERIFY, "iffresh"); // nocache,iffresh,ifexist,cacheonly,false
+            		sb.setConfig(SwitchboardConstants.SEARCH_VERIFY_DELETE, "true");
+            	}
             }
             if ("portal".equals(post.get("usecase", "")) && !"webportal".equals(networkName)) {
-                // switch to webportal network
-                sb.setConfig(SwitchboardConstants.CORE_SERVICE_RWI, false);
-                sb.switchNetwork("defaults/yacy.network.webportal.unit");
-                // switch to robinson mode
-                sb.setConfig(SwitchboardConstants.INDEX_DIST_ALLOW, false);
-                sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW, false);
-                sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW_SEARCH, false);
-                // set default behavior for search verification
-                sb.setConfig(SwitchboardConstants.SEARCH_VERIFY, "ifexist"); // nocache,iffresh,ifexist,cacheonly,false
-                sb.setConfig(SwitchboardConstants.SEARCH_VERIFY_DELETE, "false");
+            	if("intranet".equals(networkName) && hasNonEmptyRemoteSolr) {
+            		/* One or more non empty remote Solr(s) attached : disallow switching from intranet to another network to prevent disclosure of indexed private documents */
+            		prop.put("setUseCase_switchError", 1);
+            	} else {
+                	if(hasNonEmptyRemoteSolr) {
+                		/* One or more non empty remote Solr(s) attached : warn the user even if not coming from intranet as indexed documents may be irrelevant for the new mode */
+                		prop.put("setUseCase_switchWarning", 2);
+                	} 
+                	
+            		// switch to webportal network
+            		sb.setConfig(SwitchboardConstants.CORE_SERVICE_RWI, false);
+            		sb.switchNetwork("defaults/yacy.network.webportal.unit");
+            		// switch to robinson mode
+            		sb.setConfig(SwitchboardConstants.INDEX_DIST_ALLOW, false);
+            		sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW, false);
+            		sb.setConfig(SwitchboardConstants.INDEX_RECEIVE_ALLOW_SEARCH, false);
+            		// set default behavior for search verification
+            		sb.setConfig(SwitchboardConstants.SEARCH_VERIFY, "ifexist"); // nocache,iffresh,ifexist,cacheonly,false
+            		sb.setConfig(SwitchboardConstants.SEARCH_VERIFY_DELETE, "false");
+            	}
             }
             if ("intranet".equals(post.get("usecase", "")) && !"intranet".equals(networkName)) {
+            	if(hasNonEmptyRemoteSolr) {
+            		/* One or more non empty remote Solr(s) attached : warn the user as the indexed documents may be public external resources out of scope for intranet/localhost domain. */
+            		prop.put("setUseCase_switchWarning", 1);
+            	} 
                 // switch to intranet network
                 sb.setConfig(SwitchboardConstants.CORE_SERVICE_RWI, false);
                 sb.switchNetwork("defaults/yacy.network.intranet.unit");