So. Who hasn't worked in an office environment that had a Phantom Shitter?
That is, a member of staff who for some reason finds it necessary to smear faeces over the walls of the office toilet cubicle wall. It seems to be an incredibly common, if under-reported phenomena. I worked in an insurance company a few years ago where it happened frequently. It has recently began at a totally different company in a different city where I work now.
I have a friend that works in "facilities management" and he says it happens all the time. People get pissed off with their managers and decide they'll even the stakes by smearing their shit on the wall of the toilets. It does sound like a reasonable reaction to your recent crap pay rise doesn't it?
Apparently this occurs often in women's toilets also, although the ladies sometimes like to mix it up with some menstrual blood.