diff --git a/build.properties b/build.properties
index 1cdd0e78a..6c7c0960f 100644
--- a/build.properties
+++ b/build.properties
@@ -3,7 +3,7 @@ javacSource=1.5
 javacTarget=1.5
 
 # Release Configuration
-releaseVersion=0.582
+releaseVersion=0.583
 stdReleaseFile=yacy_v${releaseVersion}_${DSTAMP}_${releaseNr}.tar.gz
 embReleaseFile=yacy_emb_v${releaseVersion}_${DSTAMP}_${releaseNr}.tar.gz
 proReleaseFile=yacy_pro_v${releaseVersion}_${DSTAMP}_${releaseNr}.tar.gz
diff --git a/source/de/anomic/crawler/ProtocolLoader.java b/source/de/anomic/crawler/ProtocolLoader.java
index 66a5963ea..753287154 100644
--- a/source/de/anomic/crawler/ProtocolLoader.java
+++ b/source/de/anomic/crawler/ProtocolLoader.java
@@ -28,6 +28,9 @@ package de.anomic.crawler;
 
 import java.util.Arrays;
 import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import de.anomic.plasma.plasmaHTCache;
 import de.anomic.plasma.plasmaSwitchboard;
@@ -35,6 +38,9 @@ import de.anomic.server.logging.serverLog;
 
 public final class ProtocolLoader {
 
+    private static final long minDelay = 250; // milliseconds; 4 accesses per second
+    private static final ConcurrentHashMap<String, Long> accessTime = new ConcurrentHashMap<String, Long>(); // to protect targets from DDoS
+    
     private plasmaSwitchboard sb;
     private serverLog log;
     private HashSet<String> supportedProtocols;
@@ -64,7 +70,30 @@ public final class ProtocolLoader {
     public plasmaHTCache.Entry load(CrawlEntry entry, String parserMode) {
         // getting the protocol of the next URL                
         String protocol = entry.url().getProtocol();
+        String host = entry.url().getHost();
+        
+        // check access time
+        if (!entry.url().isLocal()) {
+            Long lastAccess = accessTime.get(host);
+            long wait = 0;
+            if (lastAccess != null) wait = Math.max(0, minDelay + lastAccess.longValue() - System.currentTimeMillis());
+            if (wait > 0) {
+                // force a sleep here. Instead just sleep we clean up the accessTime map
+                long untilTime = System.currentTimeMillis() + wait;
+                Iterator<Map.Entry<String, Long>> i = accessTime.entrySet().iterator();
+                Map.Entry<String, Long> e;
+                while (i.hasNext()) {
+                    e = i.next();
+                    if (System.currentTimeMillis() > untilTime) break;
+                    if (System.currentTimeMillis() - e.getValue().longValue() > minDelay) i.remove();
+                }
+                if (System.currentTimeMillis() < untilTime)
+                    try {Thread.sleep(untilTime - System.currentTimeMillis());} catch (InterruptedException ee) {}
+            }
+        }
+        accessTime.put(host, System.currentTimeMillis());
         
+        // load resource
         if ((protocol.equals("http") || (protocol.equals("https")))) return httpLoader.load(entry, parserMode);
         if (protocol.equals("ftp")) return ftpLoader.load(entry);
         
diff --git a/source/de/anomic/plasma/plasmaSearchQuery.java b/source/de/anomic/plasma/plasmaSearchQuery.java
index c21e5f28b..bfb08c767 100644
--- a/source/de/anomic/plasma/plasmaSearchQuery.java
+++ b/source/de/anomic/plasma/plasmaSearchQuery.java
@@ -147,9 +147,8 @@ public final class plasmaSearchQuery {
 		this.maxDistance = maxDistance;
 		this.prefer = prefer;
 		this.contentdom = contentdom;
-		this.linesPerPage = lines;
-		this.offset = offset;
-		//this.maximumTime = Math.min(6000, maximumTime);
+		this.linesPerPage = Math.min(100, lines);
+		this.offset = Math.min(100, offset);
 		this.urlMask = urlMask;
 		this.domType = domType;
         this.zonecode = domainzone;
diff --git a/source/de/anomic/plasma/plasmaSearchRankingProcess.java b/source/de/anomic/plasma/plasmaSearchRankingProcess.java
index a0b2ba6a9..980417dd6 100644
--- a/source/de/anomic/plasma/plasmaSearchRankingProcess.java
+++ b/source/de/anomic/plasma/plasmaSearchRankingProcess.java
@@ -56,6 +56,7 @@ public final class plasmaSearchRankingProcess {
     public  static kelondroBinSearch[] ybrTables = null; // block-rank tables
     public  static final int maxYBR = 3; // the lower this value, the faster the search
     private static boolean useYBR = true;
+    private static final int maxDoubleDom = 20;
     
     private kelondroSortStack<indexRWIVarEntry> stack;
     private HashMap<String, kelondroSortStack<indexRWIVarEntry>> doubleDomCache; // key = domhash (6 bytes); value = like stack
@@ -259,7 +260,7 @@ public final class plasmaSearchRankingProcess {
             m = this.doubleDomCache.get(domhash);
             if (m == null) {
                 // first appearance of dom
-                m = new kelondroSortStack<indexRWIVarEntry>(-1);
+                m = new kelondroSortStack<indexRWIVarEntry>(maxDoubleDom);
                 this.doubleDomCache.put(domhash, m);
                 return rwi;
             }
diff --git a/source/de/anomic/server/serverCore.java b/source/de/anomic/server/serverCore.java
index f29e63f78..b1cbcf3d2 100644
--- a/source/de/anomic/server/serverCore.java
+++ b/source/de/anomic/server/serverCore.java
@@ -196,7 +196,7 @@ public final class serverCore extends serverAbstractBusyThread implements server
         InetAddress uAddr = s.getInetAddress();
         if (uAddr.isAnyLocalAddress()) return "localhost";
         String cIP = uAddr.getHostAddress();
-        if (cIP.equals("0:0:0:0:0:0:0:1")) cIP = "localhost";
+        if (cIP.startsWith("0:0:0:0:0:0:0:1")) cIP = "localhost";
         if (cIP.equals("127.0.0.1")) cIP = "localhost";
         return cIP;
     }
diff --git a/source/de/anomic/yacy/yacyURL.java b/source/de/anomic/yacy/yacyURL.java
index 69e97deb0..79dbd21b5 100644
--- a/source/de/anomic/yacy/yacyURL.java
+++ b/source/de/anomic/yacy/yacyURL.java
@@ -756,7 +756,12 @@ public class yacyURL implements Serializable {
     
     // checks for local/global IP range and local IP
     public boolean isLocal() {
-        if (this.hash == null) synchronized (this) {this.hash = urlHashComputation();}
+        if (this.hash == null) {
+            if (this.host.startsWith("0:0:0:0:0:0:0:1") || this.host.equals("127.0.0.1")) return true;
+            synchronized (this) {
+                this.hash = urlHashComputation();
+            }
+        }
         return domDomain(this.hash) == 7;
     }