diff --git a/src/commands/Command.cpp b/src/commands/Command.cpp
index 562e5ea7b..daaf2b336 100644
--- a/src/commands/Command.cpp
+++ b/src/commands/Command.cpp
@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <E9.h>
 #include <text.h>
+#include <util.h>
 #include <i18n.h>
 #include <Command.h>
 #include <cmake.h>
@@ -326,6 +327,8 @@ void Command::filter (std::vector <Task>& output)
   }
   else
   {
+    safety ();
+
     context.timer_filter.stop ();
     const std::vector <Task>& pending   = context.tdb2.pending.get_tasks ();
     const std::vector <Task>& completed = context.tdb2.completed.get_tasks ();
@@ -406,8 +409,11 @@ void Command::modify_task (
   const A3& arguments,
   std::string& description)
 {
+  // Coalesce arguments together into sets to be processed as a batch.
+  A3 grouped_arguments = group_arguments (arguments);
+
   std::vector <Arg>::const_iterator arg;
-  for (arg = arguments.begin (); arg != arguments.end (); ++arg)
+  for (arg = grouped_arguments.begin (); arg != grouped_arguments.end (); ++arg)
   {
     // Attributes are essentially name:value pairs, and correspond directly
     // to stored attributes.
@@ -516,3 +522,39 @@ void Command::modify_task (
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// Disaster avoidance mechanism.
+void Command::safety ()
+{
+  if (! _read_only)
+  {
+    A3 write_filter = context.a3.extract_filter ();
+    if (!write_filter.size ())  // Potential disaster.
+    {
+      // If user is willing to be asked, this can be avoided.
+      if (context.config.getBoolean ("confirmation") &&
+          confirm (STRING_TASK_SAFETY_VALVE))
+        return;
+
+      // No.
+      throw std::string (STRING_TASK_SAFETY_FAIL);
+    }
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+A3 Command::group_arguments (const A3& input)
+{
+  A3 result;
+
+  std::vector <Arg>::const_iterator arg;
+  for (arg = input.begin (); arg != input.end (); ++arg)
+  {
+    // TODO Create a grouped set of args.
+
+    result.push_back (*arg);
+  }
+
+  return result;
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/src/commands/Command.h b/src/commands/Command.h
index ed7abe7a4..d8c2acf24 100644
--- a/src/commands/Command.h
+++ b/src/commands/Command.h
@@ -63,6 +63,10 @@ protected:
   void modify_task_annotate (Task&, const A3&);
   void modify_task (Task&, const A3&, std::string&);
 
+  void safety ();
+
+  A3 group_arguments (const A3&);
+
 protected:
   std::string _keyword;
   std::string _usage;
diff --git a/src/en-US.h b/src/en-US.h
index a9312cd26..148937431 100644
--- a/src/en-US.h
+++ b/src/en-US.h
@@ -433,6 +433,8 @@
 #define STRING_TASK_VALID_RECUR      "The recurrence value '{1}' is not valid."
 #define STRING_TASK_VALID_WAIT_RECUR "You cannot create a task that is both waiting and recurring."
 #define STRING_TASK_VALID_PRIORITY   "Priority values may be 'H', 'M' or 'L', not '{1}'."
+#define STRING_TASK_SAFETY_VALVE     "This command has no filter, and will modify all tasks.  Are you sure?"
+#define STRING_TASK_SAFETY_FAIL      "Command prevented from running."
 
 // Taskmod
 #define STRING_TASKMOD_BAD_INIT      "Taskmod::getUuid(): Task object not initialized."
diff --git a/test/bug.annotate.t b/test/bug.annotate.t
index 3b541d963..a5c4505f4 100755
--- a/test/bug.annotate.t
+++ b/test/bug.annotate.t
@@ -28,43 +28,36 @@
 
 use strict;
 use warnings;
-use Test::More tests => 9;
+use Test::More tests => 5;
 
 # Create the rc file.
-if (open my $fh, '>', 'bug_annotate.rc')
+if (open my $fh, '>', 'bug.rc')
 {
   print $fh "data.location=.\n";
   close $fh;
-  ok (-r 'bug_annotate.rc', 'Created bug_annotate.rc');
+  ok (-r 'bug.rc', 'Created bug.rc');
 }
 
 # Attempt a blank annotation.
-qx{../src/task rc:bug_annotate.rc add foo};
-my $output = qx{../src/task rc:bug_annotate.rc 1 annotate};
+qx{../src/task rc:bug.rc add foo};
+my $output = qx{../src/task rc:bug.rc 1 annotate};
 like ($output, qr/Additional text must be provided/, 'failed on blank annotation');
 
 # Attempt an annotation without ID
-$output = qx{../src/task rc:bug_annotate.rc annotate bar};
-like ($output, qr/ID needed to apply an annotation./, 'failed on annotation without ID');
+$output = qx{echo "-- n" | ../src/task rc:bug.rc annotate bar};
+like ($output, qr/Command prevented from running/, 'Filter-less write command inhibited');
+
+$output = qx{echo "-- y" | ../src/task rc:bug.rc annotate bar};
+unlike ($output, qr/Command prevented from running/, 'Filter-less write command permitted');
 
 # Cleanup.
-unlink 'pending.data';
-ok (!-r 'pending.data', 'Removed pending.data');
-
-unlink 'completed.data';
-ok (!-r 'completed.data', 'Removed completed.data');
-
-unlink 'undo.data';
-ok (!-r 'undo.data', 'Removed undo.data');
-
-unlink 'backlog.data';
-ok (!-r 'backlog.data', 'Removed backlog.data');
-
-unlink 'synch.key';
-ok (!-r 'synch.key', 'Removed synch.key');
-
-unlink 'bug_annotate.rc';
-ok (!-r 'bug_annotate.rc', 'Removed bug_annotate.rc');
+unlink qw(pending.data completed.data undo.data backlog.data synch.key bug.rc);
+ok (! -r 'pending.data'   &&
+    ! -r 'completed.data' &&
+    ! -r 'undo.data'      &&
+    ! -r 'backlog.data'   &&
+    ! -r 'synch_key.data' &&
+    ! -r 'bug.rc', 'Cleanup');
 
 exit 0;