What happened
French President Emanuel Macron last night vowed in a national address to punish those who torched public buildings, looted stores and committed other violence during a weekend of largely peaceful anti-government protests. The Interior Ministry said about 550,000 people took part in Saturday’s demonstrations, including 110,000 in Paris, and more than 2,000 people were arrested.

Who said what
Most protesters “demonstrated to state legitimate claims,” but “those who destroyed must pay,” Macron said. “Those who sought to bring down the Republic will be held accountable.” He blamed the violence on “seditious elements from far-left factions, joined by numerous delinquents.” 

Trade unions, farmers and leftist parties joined the protests as a weeks-old student-led uprising “converged with broader discontent over planned budget cuts, high energy prices and other grievances with the government,” The Washington Post said. The “most shocking” image from the weekend’s “trail of destruction” across France was the “charred shell” of the 143-year-old city hall in Limoges, torched by masked rioters.

What next?
As the “chaos subsided” yesterday, “political leaders blamed each other for the unrest and citizens looked on with shock” at their wreckage-strewn cities, The New York Times said. Macron said he had asked his government to gather students, teachers, unions and other stakeholders this week to discuss “concrete proposals” to resolve the protests.

What happened
Israeli police today said they arrested 10 suspects in connection with settler attacks in the occupied West Bank, including Friday’s brutal beating of Washington Post photographer Heidi Levine (pictured above) and an assault Saturday on a delegation of European diplomats and Catholic representatives. Israel had “come under heavy international criticism for the attacks,” which were carried out amid a “spike in settler violence during the annual Palestinian olive harvest season,” The Associated Press said.

Who said what
Levine, 64, suffered four broken vertebrae, two broken ribs, a nearly severed finger and an apparent stab wound after being kicked for about 10 minutes by young male settlers. U.S. Ambassador Mike Huckabee condemned the attack as a “despicable act of terror carried out by masked cowards.” Levine told the AP from the hospital yesterday she was “shocked and insulted” that Israeli Prime Minister Benjamin Netanyahu had downplayed the assault as “alleged,” but Israeli President Isaac Herzog and opposition leaders had reached out and sharply condemned the attacks. 

What next?
Netanyahu, whose “government is dominated by West Bank settlers and their supporters,” is “two weeks out from close elections that could end his time in power,” the AP said. President Donald Trump endorsed him on social media yesterday, calling him a “Great Warrior Prime Minister, and an even greater Partner for Peace” in Iran.

You may be able to turn your tattoos on and off in the near future. A new type of tattoo ink uses light to make the body markings appear and disappear. The result is customizable body art.

PhotoTat is “permanent yet rewritable,” said a study published in the journal Matter & Light. Scientists engineered the tattoo ink to be “nearly invisible at rest, colored within seconds under ultraviolet light and erased by white light.” It’s “made from dyes and a plexiglass-like material common in many medical technologies on the market today, including dermal fillers,” Cell Press said in a release about the study.

To develop the UV-activated ink, researchers used three photochromes, or “molecules that can change color in response to different wavelengths of light,” said The Scientist (a sister site of The Week). These molecules were then encapsulated in polymethyl methacrylate nanoparticles, which are known for their “safety record and biocompatibility.” The three colors — blue, magenta and yellow —are mixed in different combinations and ratios, producing 16 different colors.

PhotoTat can be “combined with conventional tattoo ink,” said Live Science. A permanent black ink design “could contain hidden PhotoTat elements that appear only when activated.” 

The photosensitive ink is ideal for people who “love tattoos and have lots of tattoos but just want something kind of fun and playful,” said study co-author Carson Bruns to Live Science. And it can also have practical applications, such as medical tattoos for cancer patients undergoing radiation therapy.