Introduction
In a world where privacy and security are constantly challenged, a creative method of surveillance has emerged: hiding a Bluetooth tracker inside a mailed item to follow the movements of a vessel. This technique was famously demonstrated by Dutch journalist Just Vervaart, who, following government-published guidelines, mailed a postcard containing a hidden tracker to a Dutch naval ship. The tracker remained active for about a day, revealing the ship's route from Heraklion, Crete, toward Cyprus, potentially exposing the location of an entire carrier strike group. While the tracker was eventually discovered and disabled within 24 hours of the ship's arrival—during routine mail sorting—the incident prompted the Dutch navy to ban electronic greeting cards, which, unlike packages, were not previously X-rayed before being brought aboard. This guide provides a step-by-step approach to replicating such a covert tracking operation, emphasizing the materials needed, the procedure, and critical considerations for success.
What You Need
- Bluetooth Tracker: A small, battery-powered device such as an Apple AirTag, Tile, or similar. Ensure it is fully charged and has a fresh battery.
- Mail Item: A postcard, greeting card, or letter. Avoid packages, as they are often X-rayed. (Note: electronic greeting cards are now banned by the Dutch navy due to this incident.)
- Adhesive: Strong double-sided tape, glue, or a thin adhesive pouch to secure the tracker inside the mail item.
- Envelope (optional): If using a letter or card, a standard envelope may be needed. However, postcards are more discreet because they are less likely to be X-rayed.
- Smartphone: With the corresponding app installed (e.g., Find My for AirTag, Tile app) to monitor the tracker's location.
- Address and Postage: The target vessel's mailing address (often obtainable through public records or naval communication channels) and sufficient postage.
- Tools: Scissors, tweezers, or a thin knife for precise placement.
Step-by-Step Guide
Step 1: Choose and Prepare Your Bluetooth Tracker
Select a tracker that is both small and reliable. For maximum discretion, opt for a model that allows you to disable any audible alerts—such as the speaker on some AirTags—to avoid detection when the item is handled. Remove any packaging and verify the battery is fully charged. If possible, pair the tracker with your smartphone before hiding it to confirm it is functioning correctly. Keep in mind that trackers have a limited range (typically 30-100 meters for Bluetooth), but they relay location via nearby devices (e.g., iPhones for AirTags) to create a network-based location history.
Step 2: Select the Right Mail Item
The choice of mail item is critical. Based on the original incident, postcards are ideal because they are not X-rayed before being brought onto a ship—packages are routinely scanned, increasing the risk of discovery. However, after the Dutch navy incident, electronic greeting cards (those with batteries or circuits) are now banned. Therefore, a simple paper postcard or a plain greeting card without any electronic components is safest. Ensure the item is thin enough to pass through mail sorting machines without damage but thick enough to conceal the tracker. A postcard with a stiff backing works well.
Step 3: Conceal the Tracker Inside the Mail Item
Carefully create a hidden pocket within the mail item. For a postcard, you can carefully separate the two layers of cardboard along one edge using a thin knife, then slide the tracker inside. Alternatively, attach the tracker to the inner surface of a greeting card using strong double-sided tape, then seal the card. Avoid using glue that might warp the paper or leave residue. Ensure the tracker lies flat and does not create a bulge that would raise suspicion during handling. If using an envelope, place the tracker between layers of paper or inside a folded sheet. Test that the tracker's signal can still penetrate the paper—most Bluetooth signals pass through thin materials easily.
Step 4: Address and Mail the Item
Write the target vessel's mailing address clearly on the front of the postcard or envelope. Use a return address that is untraceable if possible (e.g., a vacant lot or a fake business). Add the correct postage and drop the item into a public mailbox or at a post office counter. Timing is important: mail the item so it arrives when the ship is at port or expected to depart soon. In the original case, the postcard was likely sent to the ship's home port or a forward base. Research the vessel's schedule through public sources such as naval notices or shipping news.
Step 5: Monitor the Tracker's Location
Once the mail item is on its way, open the tracker's app on your smartphone. For AirTags, the Find My app can show the item's location on a map, updated whenever the tracker comes within range of any iOS device. Similarly, Tile uses the Tile network. You will need to remain within Bluetooth range of the tracker initially—or rely on the network—but note that the signal is only as strong as the density of devices near the target. In the open sea, coverage may be sparse, but ports and coastal areas offer better tracking. In the journalist's case, the ship's route was visible for about a day until it moved beyond network range or the tracker was disabled.
Step 6: Understand Detection Risks and Countermeasures
Be aware that mail on naval ships is often sorted and screened. The original tracker was discovered within 24 hours of the ship's arrival, during mail sorting. Since then, the Dutch navy has banned electronic greeting cards and likely increased inspections. To mitigate detection, choose a tracker that is completely non-metallic and non-reflective, or camouflage it within the mail item. However, no method is foolproof. If the ship employs electronic warfare or signal detection, even a passive Bluetooth tracker may be located. The longer the tracker remains active, the higher the risk of discovery.
Tips for Success and Ethical Considerations
- Know the legal landscape: Hiding a tracker on someone else's property without consent is illegal in many jurisdictions. This guide is for informational and historical context only. The journalist's actions were part of a journalistic investigation into security vulnerabilities.
- Consider alternative tracking methods: If you are a researcher or journalist, consider obtaining permission or using publicly available AIS (Automatic Identification System) data instead of physical trackers.
- Be prepared for rapid detection: As the Dutch navy demonstrated, security personnel are becoming more vigilant. The tracker in the incident was disabled almost immediately upon discovery.
- Use disposable trackers: If you must proceed, use a low-cost tracker with a short battery life to minimize the impact if captured.
- Test your setup: Before mailing, practice the concealment on a dummy item and confirm the tracker still works after handling and mailing processes.
- Avoid electronic greeting cards: These are now explicitly banned by some naval forces due to this incident. Stick to simple paper items without any electronic components.
- Think about the ethical implications: Tracking a military vessel could pose risks to national security and endanger lives. Always weigh the potential consequences against the value of the information.