Returning to the debate on terrorist material on the internet after the London Bridge attack in June 2017, Hannigan commented on the polarised stand-off between politicians and tech companies. He noted an improved relationship between the Silicon Valley companies and government since 2014, but called on the big companies to come together to address extremism and to preserve the freedom of the internet from state control. Interviewed alongside his former counterpart Admiral Michael Rogers, Head of the NSA and US Cyber Command, at the 2017 Aspen Security Forum, Hannigan said that since 2014 the companies had accepted responsibility for the content they carried and were making progress on extremist material, pointing to Mark Zuckerberg's comments on the subject.