Apple unveiled three new iPhones at its big September event on Tuesday, including the high-end iPhone X, which comes with a new behavior to unlock the device, known as Face ID. While Apple touted the rise in security of its facial recognition engineering, it’s unclear whether law enforcement could use it against you.

During the event, Apple senior vice president of marketing Phil Schiller said that the facial acknowledgment engineering can adapt as your face changes. “Face ID discovers your face. It reads whom you, ” said Schiller. This includes changes such as growing facial hair, wearing makeup or other adjustments people might construct to their face.

However, there are concerns that, if a situation starts where the police need to access someone’s iPhone, they could theoretically hold it up to someone’s face to gain access. NSA whistleblower Edward Snowden, for example, warned that the technology could be abused.