Bluetooth tagging devices are catching on, and keeping an eye out on the world in ways never before possible. For that relative who is always losing track of their keys or wallet, these devices from Apple, Samsung and some niche gadget players like Life360, offer a new approach to minding belongings. For pet owners, these Bluetooth devices can be used as a cheaper alternative to microchipping your dog.

“If you’re someone who forgets your keys, or your purse, or your child, and you want to track them, then these are not a bad way to do that,” said Justin Cappos, associate professor of Computer Science and Engineering at New York University Tandon School of Engineering and a member of New York University’s Center for Cybersecurity.

But the idea of tags to track people, specifically, is where the controversy has been introduced as part of this technology’s adoption.

From Apple’s AirTag to Samsung’s Galaxy SmartTag to Life360’s Tile, there are many options in the Bluetooth tagging device market offering security and peace of mind, but notably, the company’s in the market, from Apple to Life360, have made clear these devices were never designed to track people — Apple’s product messaging focuses only on personal items. That doesn’t change the fact that as with most of the technological advances occurring at an accelerated rate in recent decades, from phones to social media and AI, there is never a breakthrough that arrives without a potential downside. Tags are being put to nefarious uses, including to stalk individuals.

“If you want to track somebody, that’s what these are designed for, and that’s where the problem really comes in,” Cappos said. “You have something that it’s intended use and it’s malicious use are almost identical.”

Here are some basics to know about Bluetooth tags if you’re using one already, or considering adding one to your tech-enabled life.

The risk of stalking is real, tech companies are addressing it

There have been several crimes reported involving the use of Bluetooth tagging devices to stalk victims, specifically younger women and women being stalked by former spouses or relationship partners. Attaching these devices to cars has been common, but there have been cases of victims finding these trackers on themselves — one victim reported a Bluetooth tagging device taped inside her duffel bag and another found one hidden in her coat after a night out.

“The problem with Bluetooth trackers … is there’s no way to prevent a victim from being stalked by one of these devices because they don’t control it. They don’t have any access to it. … Whether it’s a creep at the bar or an angry ex-partner, this is a new avenue that they can use to non-consensually track somebody without their knowledge,” said Adam Dodge, CEO of digital safety education company EndTAB and a member of the World Economic Forum’s Digital Justice Advisory Committee.

Two women recently filed a class-action lawsuit against Apple alleging lack of protections the AirTag has against stalking. One victim discovered that her ex-boyfriend had planted an AirTag on her car, while the other found multiple AirTags in her child’s backpack that she suspects were placed by a former spouse.

The lawsuit is a step in the right direction, Dodge said, because tech companies have historically been insulated by Section 230 of the federal Communications Decency Act but in this case, it is a product liability issue alleging inherently dangerous products lacking sufficient safeguards.

He does give Apple credit for working to address these issues. “Apple’s already taken a lot of steps to make them less effective stalking tools. The problem is they’re really good at stalking people,” Dodge said.

For that reason, the litigation could ultimately produce positive effects, even if it’s tough to beat big tech in court. “The history of litigation against big tech for these types of circumstances is not great. But I’m hopeful that they will have success fr