There's a little more to the tale - East Coast rail being nationalised when failing and then privatised once it returned to health (http://www.theguardian.com/commentisfree/2014/nov/27/privati...) and the Govt selling off its Eurostar share prior to it becoming more valuable (http://www.theguardian.com/business/2015/nov/06/eurostar-sel...). Also for some reason TfL remains in public hands - maybe because it's too important for private sector to mess up?