"Well, I mean, the real attack on truth is tabloid journalism in the United States"

Julian Assange is referring to the way in which tabloid journalism in the United States has actually become a threat to fact. Tabloid journalism is typically sensationalized and focuses on stories that are not necessarily based in truth. This type of journalism can be harming to the general public's understanding of reality, as it can cause the spread of misinformation and incorrect stories. Assange is most likely suggesting that this type of journalism is a genuine attack on fact, as it can result in the public thinking in stories that are not based in truth. He is likely advocating for more accountable journalism that is based in facts and reality, rather than sensationalized stories that are not necessarily real.