That would be a good argument over not permitting a unilateral notification of a match (which, at the very least, I wanted to make very expensive and thus profitable, if it's allowed at all). If it notified both people 100% of the time, and one of you was a possible impostor, you could report them. And from a legal standpoint, showing interest in a market doesn't make you guilty. And, you could possibly also build "cred" in one of these tagged "markets" by getting cred from others who say you're legit, and that information would be revealed at the same time (possibly at your discretion).
Makes sense. You still might get honeypots though; could you make cred work more generally with trust between friends, friends of friends etc. without compromising the markets?