diff --git a/app/controllers/report_controller.rb b/app/controllers/report_controller.rb
--- a/app/controllers/report_controller.rb
+++ b/app/controllers/report_controller.rb
@@ -215,4 +215,18 @@
     @struggle = @struggle[0..50]
   end
 
+
+  def multiple_login
+    raw = Submission.joins(:user).joins(:problem).where("problems.available != 0").group("login,ip_address").order(:login)
+    last,count = 0,0
+    @multiple = []
+    raw.each do |r|
+      if last != r.user.login
+        count = 1
+      else
+        @multiple << r
+      end
+    end
+  end
+
 end
diff --git a/app/views/report/_report_menu.html.haml b/app/views/report/_report_menu.html.haml
--- a/app/views/report/_report_menu.html.haml
+++ b/app/views/report/_report_menu.html.haml
@@ -5,3 +5,4 @@
   = link_to '[Hall of Fame]', :action => 'problem_hof'
   = link_to '[Struggle]', :action => 'stuck'
   = link_to '[Login]', :action => 'login_stat'
+  = link_to '[Multiple Login]', :action => 'multiple_login'
diff --git a/app/views/report/multiple_login.html.haml b/app/views/report/multiple_login.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/report/multiple_login.html.haml
@@ -0,0 +1,20 @@
+- content_for :header do
+  = stylesheet_link_tag 'tablesorter-theme.cafe'
+  = javascript_include_tag 'local_jquery'
+
+%h1 Login status
+
+=render partial: 'report_menu'
+
+%table.tablesorter-cafe#my_table
+  %thead
+    %tr
+      %th login
+      %th full name
+      %th IP
+  %tbody
+    - @multiple.each do |l|
+      %tr{class: cycle('info-even','info-odd')}
+        %td= link_to l[:login], controller: 'users', action: 'profile', id: l[:id]
+        %td= l[:full_name]
+        %td= l[:ip_address]