Ouch! I bet that hurt.
I cannot absentmindedly cross the red line in a museum without feeling like I'd drawn a moustache on the Mona lisa. Actually, while in the WC in the National Gallery (London) I was tempted to sign a urinal, R Mutt, but alas, not having anything to undo the nuts and screws (I was a tourist), it wouldn't have been very authentic. Not my better ideas. I can highly recommend the toilets though. Pristine. Like they are never used.