On the use of public bathrooms

One generally assumes that public bathrooms are the filthiest, most germ infested location in a large city. Which of course is true, if we disregard the actual sewers, in which if you are not a sewage worker - whatever those people do- you would have no business being, and if you don't remember what got you there, you should be worried.

Sign in a public bathroom near the Eiffel tower in Paris : " Beware of Pickpockets ! "

Well, that is a scary sign indeed. Is this bathroom the area with the most active pickpockets? Or are they assuming that everybody eventually goes to the toilet, and therefore, that's where all the important signs must be put, including missing persons, public announcements, etc ..?
Are these pickpockets hiding in the toilet? Or do they approach you while easing the tension of your bladder, and bump into you by "accident" ?. If that's the case, they will probably be subjected to some pretty heavy spraying, making them easily detectable by specially trained french poodles, that can detect the smell of someone sprayed by urine other than his own in an "accidental" bumping.
" what about the...other thing?" I can hear some of you ask. Well I suppose some people, who are either big babies, homeless, or otherwise very desperate, DO defecate in public bathrooms. Why don't I defecate in a public bathroom? Well, it's not the actual process, but the idea that I have to sit - with my pants down- on something that was sat on by hundreds of people, each of them contributing to the already exotic population inhabiting the area, and taking all these things and snugly stowing them in my underpants is not an appealing thought to me. Ofcourse, there is an exception to this rule. The one and only time I would sit on the gaping mouth of a public toilet seat, is when I have to urinate in a trans-city train in France. Believe me, if you try to aim in a moving vehicle, you would suffer a very messy failure.