Well, I was thinking of a small number of whackos who make a practice of striking various victims with whipped-cream pies by sneaking up on their targets and pushing the pie, or throwing it, into their faces, thus "pieing" their victim.

In this construction, "guttersnipe" (a low-life) also resonates with the word "sniper" -- one who shoots unsuspecting targets from a place of hiding.

But I still disapprove of verbing the pastry.

A