I do find things like this interesting. There's a fascinating book by the journalist Jon Ronson called "so you've been publicly shamed" which looks at how the internet is used to administer "justice".
Perhaps clubs should have a system set-up in advance to deal with this kind of (very minor) vandalism so that we don't accidentally fuel any witch hunts. Having one individual speak with those involved would probably be the most effective way at preventing this sort of thing in a fair way.
It makes me think of the chamber in Eglwys where, along with the newer stuff, you can find >300 year old graffiti. It's absolutely amazing to think of cavers scratching their names into the rock all that time ago, and I think that there is some value to that old social history. The issue here is where and how it's been done, whilst the behaviour in the chamber in Eglwys seems to have been allowed by some consensus.