Robbery Filmed at the European Fine Art Fair

It looks like police may have caught 2 of the fellows: https://twitter.com/POL_Limburg/status/1541740088786288641

Is taking the sledgehammer with you a good thing? I mean, it may have fingerprints, but it makes you a bit conspicuous.

Why does smash-and-grab continue to work? Why wasn't that protected by lexan or something?