The New York Police Department has employed new technology and partnered with law-enforcement agencies around the globe to fight a surge in graffiti on New York City subway trains that has been fueled by social media, law-enforcement officials said.

Major graffiti incidents, in which trains are taken out of service for cleaning due to large mural-like paintings, have increased in recent years as more vandals share images of their work on Instagram and Twitter, according to NYPD officials.

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