diff --git a/src/main/java/fr/themode/demo/PlayerInit.java b/src/main/java/fr/themode/demo/PlayerInit.java
index 28d08d49b..2b14bd1a8 100644
--- a/src/main/java/fr/themode/demo/PlayerInit.java
+++ b/src/main/java/fr/themode/demo/PlayerInit.java
@@ -143,7 +143,6 @@ public class PlayerInit {
             });
 
             player.setEventCallback(PlayerLoginEvent.class, event -> {
-                System.out.println("event:  " + instanceContainer.hashCode());
                 event.setSpawningInstance(instanceContainer);
             });
 
diff --git a/src/main/java/fr/themode/minestom/data/DataContainer.java b/src/main/java/fr/themode/minestom/data/DataContainer.java
index cbf292d99..793de0f87 100644
--- a/src/main/java/fr/themode/minestom/data/DataContainer.java
+++ b/src/main/java/fr/themode/minestom/data/DataContainer.java
@@ -20,10 +20,8 @@ public interface DataContainer {
     default void saveData(File file, Runnable callback) {
         IOManager.submit(() -> {
             Data data = getData();
-            if (data == null) {
-                // TODO error trying to save null data
-                return;
-            }
+            if (data == null)
+                throw new NullPointerException("You cannot save null data!");
 
             try (FileOutputStream fos = new FileOutputStream(file)) {
                 byte[] serializedData = data.getSerializedData();
diff --git a/src/main/java/fr/themode/minestom/data/DataManager.java b/src/main/java/fr/themode/minestom/data/DataManager.java
index 21a46581d..6f979575b 100644
--- a/src/main/java/fr/themode/minestom/data/DataManager.java
+++ b/src/main/java/fr/themode/minestom/data/DataManager.java
@@ -22,6 +22,8 @@ public class DataManager {
         registerType(Double.class, new DoubleData());
 
         registerType(String.class, new StringData());
+
+        registerType(Data.class, new DataData());
     }
 
     public <T> void registerType(Class<T> clazz, DataType<T> dataType) {
diff --git a/src/main/java/fr/themode/minestom/data/type/DataData.java b/src/main/java/fr/themode/minestom/data/type/DataData.java
new file mode 100644
index 000000000..977cc982e
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/data/type/DataData.java
@@ -0,0 +1,25 @@
+package fr.themode.minestom.data.type;
+
+import fr.themode.minestom.data.Data;
+import fr.themode.minestom.data.DataType;
+import fr.themode.minestom.io.DataReader;
+
+import java.io.IOException;
+
+// Pretty weird name huh?
+public class DataData extends DataType<Data> {
+    @Override
+    public byte[] encode(Data value) {
+        try {
+            return value.getSerializedData();
+        } catch (IOException e) {
+            e.printStackTrace();
+            throw new IllegalArgumentException("error while writing the data");
+        }
+    }
+
+    @Override
+    public Data decode(byte[] value) {
+        return DataReader.readData(value, false);
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/instance/Instance.java b/src/main/java/fr/themode/minestom/instance/Instance.java
index 2e7c316a4..002eaece4 100644
--- a/src/main/java/fr/themode/minestom/instance/Instance.java
+++ b/src/main/java/fr/themode/minestom/instance/Instance.java
@@ -10,6 +10,7 @@ import fr.themode.minestom.instance.block.Block;
 import fr.themode.minestom.instance.block.BlockManager;
 import fr.themode.minestom.instance.block.CustomBlock;
 import fr.themode.minestom.net.PacketWriterUtils;
+import fr.themode.minestom.net.packet.server.play.BlockActionPacket;
 import fr.themode.minestom.net.packet.server.play.ChunkDataPacket;
 import fr.themode.minestom.utils.BlockPosition;
 import fr.themode.minestom.utils.ChunkUtils;
@@ -176,6 +177,19 @@ public abstract class Instance implements BlockModifier, DataContainer {
         return getCustomBlock(blockPosition.getX(), blockPosition.getY(), blockPosition.getZ());
     }
 
+    public void sendBlockAction(BlockPosition blockPosition, byte actionId, byte actionParam) {
+        short blockId = getBlockId(blockPosition);
+
+        BlockActionPacket blockActionPacket = new BlockActionPacket();
+        blockActionPacket.blockPosition = blockPosition;
+        blockActionPacket.actionId = actionId;
+        blockActionPacket.actionParam = actionParam;
+        blockActionPacket.blockId = blockId; // FIXME: block id and not block state?
+
+        Chunk chunk = getChunkAt(blockPosition);
+        chunk.sendPacketToViewers(blockActionPacket);
+    }
+
     public Data getBlockData(int x, int y, int z) {
         Chunk chunk = getChunkAt(x, z);
         return chunk.getData((byte) (x % 16), (byte) y, (byte) (z % 16));
diff --git a/src/main/java/fr/themode/minestom/net/packet/PacketReader.java b/src/main/java/fr/themode/minestom/net/packet/PacketReader.java
index 2c1bcd106..aec6a9438 100644
--- a/src/main/java/fr/themode/minestom/net/packet/PacketReader.java
+++ b/src/main/java/fr/themode/minestom/net/packet/PacketReader.java
@@ -57,6 +57,7 @@ public class PacketReader {
         ByteBuf buf = buffer.readBytes(length);
         byte[] bytes = new byte[buf.readableBytes()];
         buf.readBytes(bytes);
+        buf.release();
         return new String(bytes);
     }
 
@@ -65,6 +66,7 @@ public class PacketReader {
         ByteBuf buf = buffer.readBytes(length);
         byte[] bytes = new byte[buf.readableBytes()];
         buf.readBytes(bytes);
+        buf.release();
         return new String(bytes);
     }
 
@@ -72,6 +74,7 @@ public class PacketReader {
         ByteBuf buf = buffer.readBytes(buffer.readableBytes());
         byte[] bytes = new byte[buf.readableBytes()];
         buf.readBytes(bytes);
+        buf.release();
         return bytes;
     }