A new AI security system for airports can pick out every little detail about you. And then it follows you.

Hitachi’s new AI system can classify people based on more than a hundred characteristics, including your gender, what you’re wearing, what you’re carrying, how old you are and how you’re walking.

It’s being developed to help make you safer, says Hitachi.

“In Japan, the demand for such technology is increasing because of the Tokyo 2020 Olympics,” said senior researcher Tomokazu Murakami, who demonstrated the software, “but for us, we’re developing it in a way so that it can be utilized in many different places, such as train stations, stadiums, and even shopping malls.”

The software can be used to flag and monitor suspicious behavior, say, or help find missing children. The software can be instructed to track people with certain characteristics, but it can also find people in a crowd.

Privacy advocates see a couple of problems with such software. It erodes your right to privacy in a public space, says Privacy International’s policy officer, Frederike Kaltheuner. And, importantly, it opens the door to profiling, because even though it might appear to be a neutral machine, someone has to tell it what to look for.

“The way these systems are programmed,” Kalthenuer said, “there’s no way for them to be neutral because the suspicious behavior is not a scientific fact. It’s something you have to define when you build this system.”

And that can lead to problems. “You can employ and develop these systems with the best intentions in mind, and then they’re used by people who want to identify alcoholics, or who want to identify people of a certain race.”

The software is expected to be rolled out for corporate customers within two years.