A few years ago, spotting a hidden camera required either obvious hardware — a fisheye lens in a smoke detector, a pinhole drilled into a wall — or expensive RF detection equipment used by security professionals. Today, the calculus has changed completely.

Camera glasses that look indistinguishable from a normal pair of frames are available for under $50. Products like Meta Ray-Ban, Snap Spectacles, and dozens of lesser-known alternatives can record 1080p video from a first-person perspective without drawing a second glance. The person sitting across from you at a coffee shop, attending your meeting, or standing next to you in an elevator may be recording — and you would never know.

That's the problem Sightline was built to address.

The Recording Gap

There is a growing asymmetry between the people who carry recording devices and the people being recorded. The hardware has become cheap, miniaturized, and socially normalized. A pair of glasses is no longer a camera — it's a fashion accessory that happens to record. A small clip-on device blends into a shirt collar. A wristband logs everything in its field of view.

Meanwhile, the people in the room have no tools. There is no built-in indicator on your phone that says "a recording device is nearby." There is no standard warning. There is no awareness layer at all — unless you know what to look for and have the equipment to look.

"The right to be recorded is increasingly assumed by the people holding the hardware, while the right to know you're being recorded belongs to almost no one."

This isn't a theoretical concern. Hidden cameras have been found in Airbnb rentals, hotel rooms, changing rooms, and office spaces. Wearable cameras have been used to record private conversations without consent. As the hardware becomes more capable and more affordable, the frequency of these incidents is rising — not falling.

Why Existing Tools Fall Short

RF (radio frequency) detectors can identify wireless transmissions, but most modern camera glasses use Bluetooth rather than continuous RF, making them invisible to traditional detectors. Lens detection tools require expensive hardware or controlled lighting conditions. There is no consumer-grade, passive, always-available solution.

Sightline works differently. Modern camera glasses and wearable recording devices communicate via Bluetooth Low Energy — they advertise their presence wirelessly, even when they're not actively streaming. Sightline's BLE scanner passively listens for these advertisements and matches them against a database of known device signatures.

No special hardware. No active transmission. No RF detector needed. Just your phone, scanning passively in the background.

What Sightline Does and Doesn't Do

We want to be direct about what Sightline is and isn't, because the problem space invites overstatement.

Sightline detects Bluetooth-enabled camera glasses and wearable recording devices that are advertising nearby. It surfaces their presence so you're aware.

Sightline does not:

Detection is a signal, not a verdict. Our goal is to give you information you didn't have before — not to replace your judgment with ours.

Privacy as a First Principle

There's an irony in building a privacy app that itself collects data. We've tried to resolve that directly in how Sightline works.

Everything runs on your device. Detection history, device fingerprints, scan data — none of it leaves your phone unless you explicitly opt into contributing to our research database (a future feature, always opt-in). Crash reporting is anonymized. There is no account. There is no login. There is nothing we could hand over even if asked, because we don't have it.

The app is free. The core detection features will always be free. Pro exists for people who want to support the research and get an ad-free experience — not as a gate in front of safety.

An Honest Limitation You Should Know About

We've tested Sightline against real hardware — including Meta Ray-Ban glasses — and there is a limitation worth being direct about: when camera glasses are paired and actively connected to their owner's phone, they often stop broadcasting Bluetooth advertisements entirely. The signal goes silent. Sightline cannot detect a device it cannot observe.

This isn't a bug we can fix. It's a fundamental constraint of how Bluetooth works — once a device is in a connected state, it no longer needs to advertise to the world. The operating system never exposes that information to other apps. No software workaround exists.

What this means in practice: Sightline is most effective at detecting unpaired or recently-powered-on devices. A pair of glasses that someone has just put on, or that is searching for a connection, will typically be visible. A pair that has been paired and connected for some time may not be.

We document this prominently in the app and in our support materials because we believe you deserve to understand what the tool can and cannot do. Awareness built on false confidence is worse than no awareness at all.

The Larger Problem

Camera glasses are one category of a broader shift. Wearable cameras, AI pins, always-on lapel devices, and miniaturized recording hardware are becoming part of everyday life. The question of who gets to record whom, and whether the people being recorded have any say, is going to become one of the defining social debates of the next decade.

Sightline won't resolve that debate. But it gives people one tool they didn't have before: the ability to know. To see the devices that were, until now, invisible. To make an informed decision about where they are and who they're with.

That's why we built it.