Technically, of course, if a key is used, it's not "breaking" into cabs. I suspect the idiot minority will always find ways to disrupt (reflecting society in general!). I do find, though, that the railway enthusiast sector does seem to include a greater-than-average proportion of people with various mental health issues (I'm not being judgemental here, just factual, based on my experience). Most of the people affected are harmless, but some have extreme/obsessive behaviours which might lead to problems for the railway. Of course, it is widely accepted that the presence of rail enthusiasts in general has far more benefits than disbenefits - e.g. being extra eyes and ears to detect problems, etc. It would be interesting to know what proportion of people committing these acts are true railway enthusiasts - i.e. otherwise interested in (and supporters/defenders of) the railway - as opposed to more general trouble-makers.