If that is the case than it might be quite a cunning tactic which gives riot police reason to ‘righteously” intervene against the rest of protesters if they became too annoying, eventually. If ordinary people wood smash shop’s windows like that, you can bet police would crash them in an instant. It’s also possible, if shop owners would aggressively defend their property, police might rather react against them, instead of protected “anarchists”. Quite unusual, all this.