[M. Bison]

So we should make foot fetishes and other unusual sexual orientations illegal too ?

Absolutely. 

Feet generally aren't very well cleaned especially under the toe nails, but also tend to have thicker skin on them to keep out a lot of the crap on the floor from making its way into your body. If you're putting that in your mouth, then you might as well be licking the floor. If it doesn't affect you while going through your stomache, then consider this: many people tend to touch their face every so often, so it'd only be a matter of time until that stuff made it into your eyes, and then directly into your blood stream. If you do get sick, then depending on the sickness, you may get other people sick like some kind of jackass. I wouldn't consider this a healthy habit, but then again dogs seem to do it and are fine for the most part. hmm.... :o