Airbnbs are a great option if you’re looking for a more homey experience. However, it turns out some Airbnb hosts are worried about you making yourself too at home.

A viral TikTok posted by cyber security expert Marcus Hutchins goes into detail about hidden cameras placed around Airbnbs and hotel rooms — and how to spot them. The video has racked up 33.4 million views on the platform, telling viewers to check for “suspicious places.” Hutchins explains a technique where guests can use their phone flashlight and shine them at suspected items. Cameras give off a blue-ish reflection. He also mentioned this technique can work with two way mirrors.

@malwaretech Reply to @safarijackza How to find hidden cameras in AirBnBs #safety #travel ♬ original sound – Marcus Hutchins

Another TikToker, @pootersnoots, posted a video showing how to find infrared cameras. By turning off all the lights and using your camera phone, you should be able to spot them. Both mentioned the places to check are spots like shower heads, smoke detectors, alarm clocks, and holes in the wall.

This problem isn’t new. In 2015, Vice reported a story on counter surveillance artist Julian Oliver, who created a script that Airbnb guests can run that finds any Dropcam or similar WiFi-connected camera on a local network and disconnects it. Some, however, question the legality of doing so.

@pootersnoots good to know if you're getting spied on. Share this so people are aware! #phonecamera #hiddencamera #spy #illegal #privacymatters #infrared #fyp ♬ pushin P (feat. Young Thug) – Gunna & Future

It makes sense why some hosts would want to use cameras to make sure property isn’t stolen or trashed. Airbnb’s host policy states that hosts are allowed to have cameras in common areas as long as no one sleeps in the space. That means no rooms with bedrooms, sofa beds, or bathrooms. Guests must also be informed before booking the property that there are cameras and where they are on the property.

In 2019, The Atlantic published a story where a guest claimed that Airbnb had violated its own policy on hidden cameras by telling guests to confront their hosts. Guests who find hidden cameras typically get their money back and are provided other accommodations, while hosts who are caught are suspended until an investigation is complete. If the host is found at fault they are permanently taken off the platform.

So, the next time you decide to stay in an Airbnb, you might want to point the camera on your phone around the place a bit.