Index: app/models/comment.rb
===================================================================
--- app/models/comment.rb	(revision 189)
+++ app/models/comment.rb	(working copy)
@@ -36,7 +36,6 @@
 class Comment < Content
   validates_presence_of :author, :author_ip, :article_id, :body
   validates_format_of :author_email, :with => Format::EMAIL
-  validates_length_of :body_html, :minimum => 15
 
   before_validation :clean_up_author_email
   before_validation :clean_up_author_url
@@ -48,6 +47,13 @@
   has_one :event, :dependent => :destroy
   attr_protected :approved
 
+  after_create :delete_short_comments
+  def delete_short_comments
+    if self.body_html.size < 12
+      self.destroy
+    end
+  end
+
   def self.find_all_by_section(section, options = {})
     find :all, options.update(:conditions => ['contents.approved = ? and assigned_sections.section_id = ?', true, section.id], 
       :select => 'contents.*', :joins => 'INNER JOIN assigned_sections ON assigned_sections.article_id = contents.article_id', 

Index: app/controllers/mephisto_controller.rb
===================================================================
--- app/controllers/mephisto_controller.rb	(revision 188)
+++ app/controllers/mephisto_controller.rb	(working copy)
@@ -49,7 +49,7 @@
 
       @comment = @article.comments.build(params[:comment].merge(:user_id => session[:user], :author_ip => request.remote_ip, :user_agent => request.user_agent, :referrer => request.referer))
       @comment.check_approval site, request if @comment.valid?
-      @comment.save!
+      @comment.save! if params[:human] == "on"
       redirect_to dispatch_path(:path => (site.permalink_for(@article)[1..-1].split('/') << 'comments' << @comment.id.to_s), :anchor => @comment.dom_id)
     rescue ActiveRecord::RecordInvalid
       show_article_with 'errors' => @comment.errors.full_messages, 'submitted' => params[:comment]

Index: themes/site-1/simpla/templates/_comments.liquid
===================================================================
--- themes/site-1/simpla/templates/_comments.liquid	(revision 183)
+++ themes/site-1/simpla/templates/_comments.liquid	(working copy)
@@ -21,6 +21,7 @@
   <p>{{ form.email }}<label for="email"><small>Mail (will not be published)</small></label></p>
   <p>{{ form.url }}<label for="url"><small>Website</small></label></p>
   <p><textarea name="comment[body]" id="comment" cols="100%" rows="10">{{ submitted.body }}</textarea></p>
+  <p><input type="checkbox" name="human" /> I am a human (check this)</p>
   <p><input name="submit" type="submit" id="submit" value="Submit Comment" /></p>
 {% endcommentform %}