I had the pleasure of spending the week in Dublin, where Bloomsday festivities—the annual celebration of Ulysses, that modernist masterstroke of a novel by 20^th century literary luminary James Joyce—are taking place. While I did not stay through the weekend, I did explore the city, retrace some of Bloom’s fictional footsteps, and generally ponder the Irish literary tradition—including the peculiarly essential role the Celtic island played in stewarding and disseminating a body of scholarship that would eventually serve as a foundation for western civilization.

Ireland’s importance to the world of letters extends well before Joyce. Look no further than the Book of Kells. This national treasure is stored a floor beneath the Long Hall library at Trinity College, where the illuminated, bound-vellum pages lay splayed under a glass-capped dais in a darkly-lit room. The relic exemplifies the extraordinary monastic movement that in ages past swept Ireland and kept alive texts, classical and otherwise, in the face of the Roman Empire’s collapse.

Were it not for the Irish, many Latin texts might have been lost to time—or burned in barbaric bonfires. In a sense, Ireland served as a restore point, a reboot for the inherited wisdom and writings of the ancient world. One Thomas Cahill, in fact, argued just this in his two-decade-old bestseller, How the Irish Saved Civilization. (It’s an engaging read, though it admittedly lacks nuance.)

In Dublin, I could not help but consider the country’s heritage in the context of information security. What is cybersecurity but the preservation and protection of data? The safeguarding of valuable info assets? Long before computer servers and machines, there were monks and monasteries. Before hackers there were Vikings and Visigoths. Ireland and its scribes were a rare beacon at the onset of the Dark Ages.

Today devices do much of the rote work for us—replicating and reproducing our silicon-inscribed knowledge—but the ever-present threat of data loss and corruption is no less real. Raiders swarm the wires.

On this Bloomsday, we can learn a valuable lesson by Ireland’s example: Always have a backup plan.

Robert Hackett

@rhhackett

robert.hackett@fortune.com

Welcome to the Cyber Saturday edition of Data Sheet, Fortune’sdaily tech newsletter. Fortune reporter Robert Hackett here. You may reach Robert Hackett via Twitter, Cryptocat, Jabber (see OTR fingerprint on my about.me), PGP encrypted email (see public key on my Keybase.io), Wickr, Signal, or however you (securely) prefer. Feedback welcome.

THREATS

We need another way in. Apple is closing a loophole that allowed law enforcement officers to retrieve data from iPhones. The tech giant is planning a software update that will force people to enter a passcode before data can be transferred to or from the phone an hour after the device has been locked—thereby cutting off a popular means of investigator access. Some cops believe Grayshift, one of the most popular iPhone-cracking startups, already has a workaround for Apple’s software fix.

If you build it they will no longer come. Palmer Luckey, the 25-year-old entrepreneur who sold his virtual reality startup Oculus Rift to Facebook and then departed amid political controversy, is back at it with a new firm, Anduril Industries. The company has been lobbying the U.S. government to revise its plans for a physical border wall with Mexico. Stephen Levy at Wired details the new firm’s plans in a feature: “It merges VR with surveillance tools to create a digital wall that is not a barrier so much as a web of all-seeing eyes, with intelligence to know what it sees.”

You down with PGP? Security researchers disclosed a flaw in email encryption software tools that allowed just about anyone to spoof the digital signature on a message. Usually, such signatures provide assurances about the provenance of an encrypted note, since “signing” must generally be done with a person’s secret, private key. The researchers found a way to fake signatures using people’s public keys. Encrypted email clients GnuPG, Enigmail, GPGTools, and python-gnupg have all patched against the critical vulnerability.

Privacy lost. How shall we balance peoples’ right to privacy with the obligations of law enforcement? The courts have been engaged in figuring out the boundaries between the two sides for decades. This expansive and timely review in the New Yorker discusses the recent history of the law in depth. What’s at stake is nothing less than liberty.

"Hacking" is over.

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ACCESS GRANTED

Something strange has happened to our way of thinking—and as a result, even stranger things are happening to the world. We have come to believe that everything is computable and can be resolved by the application of new technologies. But these technologies are not neutral facilitators: they embody our politics and biases, they extend beyond the boundaries of nations and legal jurisdictions and increasingly exceed the understanding of even their creators. As a result, we understand less and less about the world as these powerful technologies assume more control over our everyday lives.

FORTUNE RECON

Here's a New Way to Break Facial Recognition by Jeff John Roberts

Facebook Won't Rule Out Building Eye-Tracking Technology by Erin Corbett

Apple Bars Apps from Scraping Address Books and Spamming Contacts by Glenn Fleishman

Splunk to Acquire Software Problem-Solver VictorOps for $120 Million by Robert Hackett

Retailers Beware: Facebook Will Ban Your Ads If You're 'Bad' by Kevin Kelleher

How Tech Companies Like Google Deal With Terrorists on Their Platforms by Erika Fry

Facebook Answered Congress's Questions About Data Privacy. Here Are 5 Surprising Ways They Track You by Natasha Bach

Apple Bans Cryptocurrency Mining From Its iOS and Mac App Stores by Sarah Gray

ONE MORE THING

Into the mushroom cloud. What might a nuclear attack on New York City look like? That's the question New York Magazine contemplates in this powerful, chilling thought experiment that appears in its latest magazine issue. "If nuclear war is considered 'unthinkable,' that is in no small part because of our refusal to think about it with any clarity or specificity," the author writes. "In the long run, the best deterrent to nuclear war may be to understand what a single nuclear bomb is capable of doing to, say, a city like New York—and to accept that the reality would be even worse than our fears."