# File lib/ramaze/contrib/facebook/facebook.rb, line 88
    def valid?
      return false unless respond_to?(:request) and not request['fb_sig'].nil?
      request['facebook.valid?'] ||= \
        request['fb_sig'] == Digest::MD5.hexdigest(request.params.map{|k,v| "#{$1}=#{v}" if k =~ /^fb_sig_(.+)$/ }.compact.sort.join+SECRET)
    end