Carry On, published in 2013, is the second collection of essays drawn from the schneier-on-security-blog and crypto-gram-newsletter, covering roughly 2008 to 2013. Like schneier-on-security-book, it is a curated selection of Schneier's commentary output rather than a sustained original argument. The title plays on both the British wartime phrase and the airport security practice of carrying on hand luggage — a reference to the airport security theater that Schneier had criticized throughout this period.
Content and Themes
The essays in Carry On engage the security debates of the late 2000s and early 2010s: the rise of body scanners at airports, the debate over cybersecurity legislation, the growing surveillance capabilities of commercial companies and governments, and the increasing sophistication of cyberattacks against infrastructure and individuals. The period covered includes the early visible development of state-sponsored cyber operations (Stuxnet was publicly revealed in 2010) and the growing awareness that internet infrastructure was a contested geopolitical space.
Several essays address airport and transit security directly — a consistent Schneier theme throughout the security-commentator-era. His argument is consistent: the security measures deployed after September 11 are calibrated to the specific attacks that occurred, not to the actual threat landscape. Security theater responds to yesterday's attack. Effective security requires anticipating novel attack vectors, which requires threat modeling rather than reaction.
Relationship to the Full Arc
Carry On was published in the same year as liars-and-outliers, and the contrast between the two books illustrates the dual character of Schneier's output. Liars and Outliers is theoretical, sustained, and ambitious; Carry On is practical, fragmented, and topical. Schneier operates simultaneously as a theorist developing long-term frameworks and as a commentator engaging weekly with current events. The essay collections are the output of the second mode.
The book's lasting value is similar to that of schneier-on-security-book: it is a historical record of security policy discourse at a particular moment, filtered through a consistent analytical lens. For readers who do not follow the blog continuously, the collections provide curated access to Schneier's most significant shorter work.
Note on Format
Schneier's essay collections are deliberately accessible — the pieces are short, jargon-free, and designed for general audiences. This is not a weakness but a deliberate choice. Schneier's influence during the security commentator era derived substantially from his ability to publish regularly and clearly on topics that mattered to non-specialists. The essay format is the medium through which that influence operated.