Per the article, they followed the rules to get permission to do their art installation for a specific period of time. Public parks are the perfect place for public art to be displayed and these artists went about it in exactly the right way. If you like trees strictly au naturel, you have every right to keep the trees on your private property exactly the way you like them. You can even enjoy the several million trees in the Anchorage area that are unadorned every day. A few trees in a public park wearing sweaters for 4 months surely won't hurt you in any way. I should think you could have at least some empathy for these artists, whose hard work was destroyed, and the many people who *would* have enjoyed their creative expression.