From 2008 to 2010, Cathcart was specialist adviser to the
House of Commons Select Committee on Culture, Media and Sport at a time when it was investigating press standards and the
phone-hacking scandal. The Committee report was highly critical of News International (now
News UK) and of the
Press Complaints Commission (since abolished). From 2010, Cathcart blogged on the unfolding hacking affair, mostly for
Index on Censorship, and in 2011, with Martin Moore, director of the Media Standards Trust, he launched
Hacked Off to press for a public inquiry into hacking and press standards. Cathcart served as Hacked Off’s first executive director from 2012 to 2014, writing extensively on press self-regulation and acting as the campaign's principal spokesman. He appeared before
The Leveson Inquiry twice, and his stance on press standards has drawn criticism and personal attacks from some in the industry. ==History writing==