French lawmakers propose tagging rioters with invisible markers to track them down later

The French Senate has proposed allowing police to use coded liquid markers to track down suspects weeks after disruptive demonstrations.

French lawmakers are proposing 30 recommendations following days of student protests demanding better school conditions that erupted into violent riots and looting on October 17th, 2026.

Recommendation 28.3 includes the use of coded liquid markers to “facilitate arrests at a later time.”

Coded liquid markers are small devices used to apply a liquid tag to skin and clothing, which is invisible to the naked eye.

Each marker is linked to a unique code assigned to a particular police operation, and its vaporization can reach 5 to 7 meters (16-23 feet), according to Gadget Review.

Manufacturers of coded liquid markers say they don’t pose any health risks, are painless, and odorless. The invisible tag can stay on the skin for weeks, and marked objects can be traced for months later.

Projectiles containing the marking agent are fired from a distance using a paintball-type gun. Traces can be detected later using a UV lamp.

The technology is commonly used to track down robbers. In the event of riots, police could locate suspects long after the demonstrations had dispersed.

Wrongful detention of a journalist

The wide marker’s reach, however, raises concerns about false positives, as peaceful protestors, medics, and journalists could also be tagged despite not violating any laws.

Police reportedly used marking agents during the 2023 protest in Sainte-Soline opposing the construction of a water reservoir.

According to Reporterre, the technology’s use resulted in the arrests of 2 people, including a freelance journalist for leading media outlets such as Le Monde and Radio France, who says he went there to scout locations for future stories.

The journalist, introduced by Clement B, said he was placed under policy custody for 28 hours for participation in a group that intended to “commit intentional violence against individuals or to damage property.”

Another detainee, who participated in the protest, said he spent 24 hours under custody only to learn that he had a small mark of an invisible agent between his fingers, which didn’t come from direct contact with the substance but was “transferred” by touching someone else.

Police use tech to locate troublemakers

French police made 2,400 arrests across the country while nearly 1,000 officers were injured, according to French ministry data. Over 1,500 shops were vandalized.

The proposal also suggests the use of drones and body cameras to increase accountability of troublemakers, illustrating the police’s efforts to harness the latest technology to locate rioters and looters.

Investigators are examining riot videos posted on social media, alongside the footage from approximately 80,000 cameras, according to France24.

Justice Minister Gérald Darmanin said facial recognition will be used to compare mugshots with images posted on social networks.

Following the riots, Vinted and other resale platforms were flooded with stolen goods with the hashtag “October 17,” including expensive perfume and jewelry. The company said it was actually actively collaborating with law enforcement.

The French government urged social media companies like Meta and TikTok to step up their moderation of riot-related content, including livestreams, violent material, and calls for violence and curfew violations.