I think the technical answer here is yes but, given the fact that the police themselves were too occupied to pursue the original thieves, I find it equally unli

I think the technical answer here is yes but, given the fact that the police themselves were too occupied to pursue the original thieves, I find it equally unlikely they're going to pursue the vigilante IANAL - but I'd suppose they could sue you and may even win but it's not going to do much for their public image in the best case and the worst case they get prosecuted for theft.