Some of the 'vandalism' may not be deliberate - there are people out there who seem to have no idea how to use a toilet. Someone at work is regularly blocking toilets with excessive amounts of paper and, given where I work and the people we employ, I cannot imagine that its being done deliberately - its just ignorance, laziness and, maybe, embarrassment. How hard its it to work out that if you need to use a lot of paper you use, flush, use and flush again, rather than piling it all in at once and then staring at a blocked loo?
However, living on a boat as I do maybe I am less embarrassed about and more immediately aware of waste disposal issues - we have a little tag line on my moorings 'Whenever two or more boaters gather together than they shall discuss Toilets'.
Oh, and I hate having no toilets on a train. I have long commute with a 1hr segment, due to a health issue no toilet can result in prolonged episodes of pain. I always go, if possible[1], before I get the train but thats no guarantee.
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[1] What is it with some Station Toilets? Woking Plt 2/4 Gents are regularly out of use - one working Gents urinal and one working Gents stall is not enough for a station that size. Plt 1 at Havant is regularly 'flooded'. Guildford, despite charging, is always grotty and grimy, with puddles on the floor, as hell. Finally West Byfleet no longer has any loos for the Able Bodied at all! (To be fair, for a long time West Byfleet had NO working loos, Disabled or otherwise)