I just read Vicster's post and went on to see the photo of vandalism at Castlerigg and there are striking similarities between the initials - maybe I've misread it and it says MY not MW.

http://www.themodernantiquarian.com/post/47438 is the damage at Castlerigg

http://www.themodernantiquarian.com/post/50972 is the damage I noticed yesterday.

What do you think? I’m not sure, and I’m hoping there isn’t someone consciously visiting these sites with the deliberate intention of defacing them.