[There is the slightest sense of resistance when Moriarity grabs her arm and the slightest uncomfortable eye twitch at the contact. It's a good thing he lets go once they're out of the main fray of colorful host lane. ]

I'm no great consulting detective, but I can deduce. We can look for street vendors that a scammer would target, ones who have an air of goodwill.

[ There are a few of them, like the carts selling fancy crepes or savory oden for the night workers who need a bite to eat before going back to their shift.]

It'd be harder to scam a host, I'd imagine. They're better at making one spend money then to give it out of the goodness of their hearts.