A wave of increasingly audacious art and artefact thefts is sweeping European museums, with Europol (the EU's policing agency) warning that both the frequency and violence of such crimes have risen sharply over the past two years. The trend gained momentum after last October's brazen robbery at the Louvre in Paris, where thieves used power tools and threatened guards to steal €88m worth of jewellery that remains missing — an event security experts say inspired a string of copycat crimes, including the theft of four Renoir paintings from a museum in Cagnes-sur-Mer, France, carried out in under five minutes. Criminals are shifting away from hard-to-sell paintings toward precious metals, gemstones, and culturally significant artefacts that can be melted down or discreetly traded, while museums — often housed in historic buildings with limited security budgets and open public access — struggle to keep pace with the threat.