I'm sure it breeches Health and Safety, that's why I was talking about it today, I went into work and the smell of gone off milk was horrible, but no matter how many laminated notices are up about 'cleaning after yourself' nothing works.
I'm sure it's something psychological regarding collective behaviour, but i don't enough about the subject to give it a proper name, but it's definately something to do with 'ownership'... or 'dis-ownership'