diff --git a/src/command.cpp b/src/command.cpp
index 1d0e953a8..f61c17ea2 100644
--- a/src/command.cpp
+++ b/src/command.cpp
@@ -35,6 +35,7 @@
 #include <pwd.h>
 #include <time.h>
 
+#include "Permission.h"
 #include "text.h"
 #include "util.h"
 #include "main.h"
@@ -794,6 +795,10 @@ std::string handleModify ()
   std::vector <Task> all = tasks;
   context.filter.applySequence (tasks, context.sequence);
 
+  Permission permission;
+  if (context.sequence.size () > (size_t) context.config.get ("bulk", 2))
+    permission.bigSequence ();
+
   foreach (task, tasks)
   {
     // Perform some logical consistency checks.
@@ -815,19 +820,30 @@ std::string handleModify ()
            task->get ("parent") == other->get ("parent")) || // Sibling
           other->get ("uuid")   == task->get ("parent"))     // Parent
       {
+        Task before (*other);
+
         // A non-zero value forces a file write.
         int changes = 0;
 
         // Apply other deltas.
-        changes += deltaDescription (*other);
+        if (deltaDescription (*other))
+        {
+          permission.bigChange ();
+          ++changes;
+        }
+
         changes += deltaTags (*other);
         changes += deltaAttributes (*other);
         changes += deltaSubstitutions (*other);
 
-        if (changes)
-          context.tdb.update (*other);
+        if (taskDiff (before, *other))
+        {
+          std::string question = taskDifferences (before, *other) + "Are you sure?";
+          if (changes && permission.confirmed (question))
+            context.tdb.update (*other);
 
-        ++count;
+          ++count;
+        }
       }
     }
   }
diff --git a/src/tests/util.t.cpp b/src/tests/util.t.cpp
index 260116866..4cb9d43ea 100644
--- a/src/tests/util.t.cpp
+++ b/src/tests/util.t.cpp
@@ -34,7 +34,7 @@ Context context;
 ////////////////////////////////////////////////////////////////////////////////
 int main (int argc, char** argv)
 {
-  UnitTest t (17);
+  UnitTest t (19);
 
   // TODO bool confirm (const std::string&);
   // TODO int confirm3 (const std::string&);
@@ -80,14 +80,16 @@ int main (int argc, char** argv)
 
   Task rightAgain (right);
 
-  std::string output = taskDiff (left, right);
-  t.ok (output.find ("zero was changed from '0' to '00'.\n") != std::string::npos, "Detected change zero:0 -> zero:00");
-  t.ok (output.find ("one was deleted.\n")                   != std::string::npos, "Detected deletion one:1 ->");
-  t.ok (output.find ("two")                                  == std::string::npos, "Detected no change two:2 -> two:2");
-  t.ok (output.find ("three was set to '3'.\n")              != std::string::npos, "Detected addition -> three:3");
+  std::string output = taskDifferences (left, right);
+  t.ok (taskDiff (left, right),                                                  "Detected changes");
+  t.ok (output.find ("zero was changed from '0' to '00'.") != std::string::npos, "Detected change zero:0 -> zero:00");
+  t.ok (output.find ("one was deleted.")                   != std::string::npos, "Detected deletion one:1 ->");
+  t.ok (output.find ("two")                                == std::string::npos, "Detected no change two:2 -> two:2");
+  t.ok (output.find ("three was set to '3'.")              != std::string::npos, "Detected addition -> three:3");
 
-  output = taskDiff (right, rightAgain);
-  t.ok (output.find ("No changes were made.\n")              != std::string::npos, "No changes detected");
+  t.notok (taskDiff (right, rightAgain),                                         "No changes detected");
+  output = taskDifferences (right, rightAgain);
+  t.ok (output.find ("No changes were made.")              != std::string::npos, "No changes detected");
 
   return 0;
 }
diff --git a/src/util.cpp b/src/util.cpp
index 260379d64..615553e65 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -427,7 +427,37 @@ void spit (const std::string& file, const std::string& contents)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-std::string taskDiff (const Task& before, const Task& after)
+bool taskDiff (const Task& before, const Task& after)
+{
+  // Attributes are all there is, so figure the different attribute names
+  // between before and after.
+  std::vector <std::string> beforeAtts;
+  foreach (att, before)
+    beforeAtts.push_back (att->first);
+
+  std::vector <std::string> afterAtts;
+  foreach (att, after)
+    afterAtts.push_back (att->first);
+
+  std::vector <std::string> beforeOnly;
+  std::vector <std::string> afterOnly;
+  listDiff (beforeAtts, afterAtts, beforeOnly, afterOnly);
+
+  if (beforeOnly.size () ||
+      afterOnly.size ())
+    return true;
+
+  foreach (name, beforeAtts)
+    if (*name              != "uuid" &&
+        after.get (*name)  != ""     &&
+        before.get (*name) != after.get (*name))
+      return true;
+
+  return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+std::string taskDifferences (const Task& before, const Task& after)
 {
   // Attributes are all there is, so figure the different attribute names
   // between before and after.
@@ -447,15 +477,13 @@ std::string taskDiff (const Task& before, const Task& after)
   std::stringstream out;
   foreach (name, beforeOnly)
     out << *name
-        << " was deleted."
-        << std::endl;
+        << " was deleted.  ";
 
   foreach (name, afterOnly)
     out << *name
         << " was set to '"
         << after.get (*name)
-        << "'."
-        << std::endl;
+        << "'.  ";
 
   foreach (name, beforeAtts)
     if (*name              != "uuid" &&
@@ -466,15 +494,15 @@ std::string taskDiff (const Task& before, const Task& after)
           << before.get (*name)
           << "' to '"
           << after.get (*name)
-          << "'."
-          << std::endl;
+          << "'.  ";
 
   // Can't just say nothing.
   if (out.str ().length () == 0)
-    out << "No changes were made."
-        << std::endl;
+    out << "No changes were made.  ";
 
-  return out.str ();
+  std::stringstream decorated;
+  decorated << "Task " << before.id << " was modified.  " << out.str ();
+  return decorated.str ();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/src/util.h b/src/util.h
index 2d59cf22d..422f3bc21 100644
--- a/src/util.h
+++ b/src/util.h
@@ -73,7 +73,8 @@ std::string expandPath (const std::string&);
 bool slurp (const std::string&, std::vector <std::string>&, bool trimLines = false);
 bool slurp (const std::string&, std::string&, bool trimLines = false);
 void spit (const std::string&, const std::string&);
-std::string taskDiff (const Task&, const Task&);
+bool taskDiff (const Task&, const Task&);
+std::string taskDifferences (const Task&, const Task&);
 
 #endif
 ////////////////////////////////////////////////////////////////////////////////