The Iconic Joshua Tree made famous by U2 album cover is found chopped up...

http://www.dailymail.co.uk/news/article-2971368/U2-fan-pilgrimaged-band-s-Joshua-Tree-outraged-finding-CHOPPED-California-desert.html
Even if that particular tree was inside of a steel cage, some people would have still tried to get to it. The J. Tree would have required a guard shack near it with 24 hour security.
http://www.ghosttownexplorers.org/california/U2/u2.htm

https://en.wikipedia.org/wiki/Joshua_Tree_National_Park

http://www.u2interference.com/forums/f285/rsoc-269-desert-sky-172327-3.html

http://www.nps.gov/jotr/index.htm , http://photos.calipidder.com/keyword/u2

http://bootlegpedia.com/en/product/G.R._045-046-047

http://webspace.webring.com/people/ja/aaronax70/u2.gif ,
http://hub.yourtakeonmusic.com/hub/u2bootlegs

https://en.wikipedia.org/wiki/The_Joshua_Tree#Packaging_and_title

https://desertshapes.blogspot.com/search?q=U2