diff --git a/TODO b/TODO
index 71ec04c..5040631 100644
--- a/TODO
+++ b/TODO
@@ -12,7 +12,6 @@ Coding tasks
 * On up votes karma is transferred to posting user.
 * Automatically replace all the occurrences of Hacker in comments and news titles with H4k3r
 * Trottle by IP, using our INCR+TTL trick.
-* Require a minimal delay between same user submissions. At least write a "please wait" message.
 * User profile
 * Complete the API. Missing: get news stream and a few more.
 * Handle "comment" news.
diff --git a/app.rb b/app.rb
index 584a979..d961319 100644
--- a/app.rb
+++ b/app.rb
@@ -388,6 +388,11 @@
     if not check_api_secret
         return {:status => "err", :error => "Wrong form secret."}.to_json
     end
+
+    if submitted_recently
+        return {:status => "err", :error => "You have submitted a story too recently, please wait #{allowed_to_post_in_seconds} seconds."}.to_json
+    end
+
     # We can have an empty url or an empty first comment, but not both.
     if (!check_params "title","news_id",:url,:text) or
                                (params[:url].length == 0 and
@@ -681,6 +686,16 @@ def check_user_credentials(username,password)
     (user['password'] == hp) ? [user['auth'],user['apisecret']] : nil
 end
 
+# Has the user submitted a news story in the last `NewsSubmissionBreak` seconds?
+def submitted_recently
+  allowed_to_post_in_seconds > 0
+end
+
+# Indicates when the user is allowed to submit another story after the last.
+def allowed_to_post_in_seconds
+  $r.ttl("user:#{$user['id']}:submitted_recently")
+end
+
 ################################################################################
 # News
 ################################################################################
@@ -875,6 +890,8 @@ def insert_news(title,url,text,user_id)
     $r.zadd("news.top",rank,news_id)
     # Add the news url for some time to avoid reposts in short time
     $r.setex("url:"+url,PreventRepostTime,news_id) if !textpost
+    # Set a timeout indicating when the user may post again
+    $r.setex("user:#{$user['id']}:submitted_recently",NewsSubmissionBreak,'1')
     return news_id
 end
 
diff --git a/app_config.rb b/app_config.rb
index 562dc59..1d13ad3 100644
--- a/app_config.rb
+++ b/app_config.rb
@@ -29,3 +29,4 @@
 NewsScoreLogBooster = 2
 RankAgingFactor = 1.3
 PreventRepostTime = 3600*48
+NewsSubmissionBreak = 60*15