Have you ever posed for a photo with your index and middle fingers raised, indicating your desire for world peace? Probably, since the sign has become shorthand for the sentiment after Vietnam War activists popularized it in the 1960s.

But researchers in Japan warned this week that those flashing their exposed fingertips were at risk of fingerprint theft, which in turn could be used for any number of things, like unlocking your iPhone. 

Isao Echizen, a researcher at the National Institute of Informatics, said that he and his team were able to lift the fingerprints from someone’s fingers from a photo taken about nine feet away, according to Phys.org.

The technology used to do this, Echizen says, was not very advanced, but as it so happens, the NII is developing a solution to this so-far-possibly-nonexistent-(?)-problem: a transparent film that would block thieves from decoding the tiny contours on your skin.

It won’t be ready for public use for another couple of years, though. In the meantime, think long and hard about how strong your commitment to nonviolence is before, again, choosing to flash the V sign for cameras.