I suspect that the answer here would be to use some common sense.
I'm not sure anyone would condone cyclists riding along the pavement/sidewalk - intersection or not. This is a risk to pedestrians, and generally gives cyclists a bad reputation.
But, as a motorist, what are you going to do? Drive into them?
I'm pretty sure that in most any jurisdiction, that would put you in the wrong.
Even if you did so accidentally, when you had right of way, I'm pretty sure you'd find yourself in a position where you'd have to prove your innocence, rather than someone having to prove your guilt.
Driving is a social activity in that, like it or not, we have to share the roads with other people. Try not to let the fact that some of those people (whether on 2- or 4-wheels) are idiots, ruin your day.