As lawyers and civil libertarians point out, federal criminal law is so vast and complicated that it is easy to unwittingly violate it, and even innocent conversation can later be used to build a criminal case. Encrypting your communication isn’t a matter of hiding criminal activity; it’s a matter of ensuring innocuous activity can’t be deemed suspicious by a zealous prosecutor or intelligence agent. Telling a friend that a party is really going to “blow up” when you arrive is less funny when it’s being entered into evidence against you.

Even so, for many of the people now signing up for Signal or setting up encrypted email accounts, fears of an aggressive federal government are relatively minor concerns. In some sense, as the Signal skeptics in my group of friends pointed out, people are taking part in a kind of security-state LARPing — taking up security practices the way live-action role players take up plastic swords in the park.

But the federal government isn’t the only security threat on the internet. And for most people it’s far from the most worrying. Social media is infested with roving bands of malicious hackers, far less concerned with intercepting communications for surveillance purposes than with wreaking havoc and embarrassing targets.

The hacks that exposed tens of thousands of emails from the accounts of the Clinton campaign chairman, John Podesta, and Democratic Party staff members were as loud an alarm as Mr. Trump’s election. When libraries of correspondence are dumped online unedited, they’re invitations to be picked apart, taken out of context and turned into the building blocks of bizarre and damaging pizza-based conspiracy theories. While the fantasy of oppressive government surveillance is appealing to the little Winston Smiths inside us — and is much more than a fantasy for many activists and journalists — practically, what most of us should fear isn’t Big Brother reading our emails, but everyone else.

There’s another reason to use encrypted email or messaging besides fear, anyway: herd immunity. The more widely the use of encrypted communication spreads, the less useful the dragnet tools of the intelligence community become. C.I.A. documents published by WikiLeaks last month seem to confirm this: Unable to crack Signal’s encryption for bulk collection, the agency must instead attempt the practically difficult task of installing malware on specific phones. “Ubiquitous e2e encryption is pushing intelligence agencies from undetectable mass surveillance to expensive, high-risk, targeted attacks,” Open Whisper Systems tweeted after the leak, discussing the benefits of end-to-end encryption.

But even if we’re overly paranoid — even if there’s nothing to fear from either the feds or random alt-right trouble makers — what’s wrong with security LARPing? Often without realizing it, Americans have exposed vast and previously private information about ourselves to enormous tech companies, the government and, in all likelihood, malicious actors looking to mess around. If a President Trump is what it takes for liberals to think more clearly about the security of our data and communications, so be it. At worst, security LARPing — like using Signal when GroupMe would do — is an exercise in mindfulness: a daily check on your exposure. At best, it’ll actually prevent a security breach.

In the end, my friends and I split the difference, based on our particular threat model: We upgraded our subscription to the workplace chat software Slack. Slack doesn’t have end-to-end encryption, so our messages could theoretically be intercepted, but it does include the security features we wanted most (two-factor authentication and automatic message deletion) and a handful of others we found useful (side chats dedicated to discussing various science-fiction and fantasy franchises). But we were far from the only people reconsidering our messaging choices.

These days, when I open Signal, my contact list is filled with dozens of friends, many of whom aren’t the journalists or activists who make up the app’s theoretical core user base. A few weeks ago, I asked one why he uses Signal. “Ya gotta these days,” he wrote back. “And my weed guy uses it. It’s why I downloaded it.”