Donald Trump Jr is facing a backlash for criticizing London mayor Sadiq Khan with a scornful tweet sent hours after an attack at the Houses of Parliament left four dead, including a police officer.The US president’s eldest son tweeted a link to a September 2016 story in the Independent, which quoted Khan saying terror attacks were “part and parcel of living in a big city”, and “I want to be reassured that every single agency and individual involved in protecting our city has the resources and expertise they need to respond in the event that London is attacked.”You have to be kidding me?!” Trump Jr tweeted, quoting the headline: “Terror attacks are part of living in big city, says London Mayor Sadiq Khan”.(the guardian)…[+]