Oh man that's disgusting, it completely disregards peoples property rights and right to privacy, I knew people have had issues with Home Owner Associations in the past but didn't know it was at the point the local government was digging it all up for some. I'll never understand the mentality of "That person has something I don't. I don't like that. They must be wrong. Let's destroy it and fix them." It definitely seems like a culture issue though, as your third link mentions: Victory Gardens cropped up in the UK after World War II (and presumably during...) and I think greenhouses have always been a staple of the British Garden thereafter. Many houses here don't have the front garden to spare so perhaps thats why I've not seen any (many?) stories of others interfering with peoples property, as in the back garden it's a bit more out of sight out of mind.