[Leica] Scam, but how?

[afirkin at afirkin.com (Alastair Firkin)]

We were on a bridge in Paris, when a guy came up bent down a meter or so 
away, picked up a heavy gold ring and tried to give it to me, intimating 
that it must be mine. I refused it, and thought it was odd. Was it a scam? 
He acted quite annoyed we did not take it. 

Next day the same scenario occurred at the Place de la Concorde. First a 
girl, only this time I was more aware and noted that she was holding the 
ring before putting it down and picking it up. I just waved her away and she 
kept going, then 100 meters further another, then 30 minutes later I saw 
someone doing it to someone else. 

We did not lose anything, but does anyone know where this scam goes if you 
take the ring?

Just curious

Cheers

Alastair