There have been numerous cautionary posts on social media in recent months. Many of them indicate that you may be in danger if you notice a wire on your car door handle, 1F scrawled in the snow, a coat hook in a bathroom, a USB charger in a hotel room, or even a piece of cheese on your car.

Now that a new warning has been issued, it is obvious that it must be taken seriously.

A water bottle in a driver’s wheel well alerts them to drive cautiously. According to accounts, thieves place empty containers in wheel wells, usually on the passenger side, to steal the vehicle or the driver’s belongings.

The method works because an unsuspecting driver will start their car but immediately halt when they hear the horrifying cracking of the broken bottle. Unsure of what the noise is and afraid that their car has been damaged, a driver may get out to investigate and may do so while the car is still running.

The thieves strike when the driver rounds the car and stoops beside the tire. They emerge from a nearby hiding location and either steal the car’s contents or drive away while the driver is distracted.

The water bottle trick supposedly made its premiere in South Africa, and it’s probable that similar incidences have occurred since then. Although there is some discussion over whether or not these kinds of warnings come true, this one appears to be quite plausible, and Snopes has no way of proving otherwise.

In either scenario, it’s best to be aware that it could happen. If you do decide to investigate the noise, even if it’s just to walk around your car, turn off the engine, hang on to your key, and lock your doors.