try an in query directly for the tags

app/controllers/tag_followings_controller.rb

@@ -10,7 +10,6 @@ class TagFollowingsController < ApplicationController
 
   def index
     @stream = TagStream.new(current_user, :max_time => params[:max_time], :order => sort_order)
-
     if params[:only_posts]
       render :partial => 'shared/stream', :locals => {:posts => @stream.posts}
     else

lib/stream/tag_stream.rb

@@ -18,8 +18,7 @@ class TagStream < BaseStream
       []
     else
       @posts ||= StatusMessage.owned_or_visible_by_user(user).
-        tagged_with([tag_string], :any => true).
-        where(:public => true).
+        joins(:tags).where(:tags => {:name => tag_array}).
         for_a_stream(@max_time, @order)
     end
   end
@@ -39,6 +38,10 @@ class TagStream < BaseStream
     @tag_string ||= tags.join(', '){|tag| tag.name}.to_s
   end
 
+  def tag_array
+    tags.map{|x| x.name}
+  end
+
   def tags
     @tags = user.followed_tags
   end

spec/lib/stream/tag_stream_spec.rb

@@ -4,9 +4,17 @@ require File.join(Rails.root, 'spec', 'shared_behaviors', 'stream')
 describe TagStream do
   before do
     @stream = TagStream.new(Factory(:user), :max_time => Time.now, :order => 'updated_at')
+    @stream.stub(:tag_string).and_return("foo")
   end
 
   describe 'shared behaviors' do
     it_should_behave_like 'it is a stream'
   end
+
+
+  describe 'posts' do
+    it 'explains the query' do
+      puts @stream.posts.to_sql
+    end
+  end
 end