gistfile1.rb

module Kernel
  alias_method :puts_without_check, :puts
  def puts(*args)
    args.each do |arg|
      raise "puts called, check the backtrace for the source" if arg.to_s =~ /Class:/
    end
    puts_without_check(*args)
  end

  alias_method :print_without_check, :print
  def print(*args)
    args.each do |arg|
      raise "puts called, check the backtrace for the source" if arg.to_s =~ /Class:/
    end
    print_without_check(*args)
  end
end