Watch: Hong Kong Protesters Use Lasers to Disrupt Facial Recognition

In the recent wave of demonstrations to sweep Hong Kong, tensions between protesters and police have continued to escalate.

The protests began with a simple demand for the government of mainland China to cancel a controversial extradition treaty, which would allow the government to arrest citizens of Hong Kong to face charges in China.

However, after weeks of violent clashes with government agents, the list of demands from the protesters has grown to include the release of detained activists and retribution for the police brutality seen during the demonstrations.

According to Foreign Policy, many of the protesters are now calling for all-out liberation from China and independence for Hong Kong.

The protesters in Hong Kong are fighting technologically advanced police forces, but have developed ingenious guerilla tactics to counteract the technological disadvantage.

One recent video, broadcast by Hong Kong’s Now TV, shows a large group of protesters shining laser pointers at police in order to disrupt their facial recognition cameras. Protesters have also taken additional measures, like spray painting camera lenses on the street or around government offices.

In addition to helping crowds remain anonymous by disrupting the cameras in the moment, the lasers can also cause permanent damage to the sensitive lenses on the facial recognition cameras.

According to the International Laser Display Association, “lasers emit concentrated beams of light, which can heat up sensitive surfaces”—like camera sensors—”and cause damage.”

The protesters have also come up with some clever ways of defending themselves against teargas. As you may notice in the video above with the laser pointers, many of the protesters are carrying umbrellas. The umbrellas are used as makeshift shields which protect them from the tear gas.

Many comparisons have been made to the traditional Roman battle formation in which the soldiers lock their shields together to protect the whole group from arrows and other projectiles, as seen in the image below.