At carnival in Bazil, you bump into people; Like, when they talk packed streets, they're talking body to body contact filling the street for blocks and blocks. All you'd have to do is put a terminal around your waist and you'd get close enough to activate NFC for hundreds of people just pushing through the crowd.

https://en.wikipedia.org/wiki/Brazilian_Carnival#/media/File...

If I remember correctly, yes, they had a modified terminal that picked up cards more than a meter away. But the other comment is overestimating the damage, there is no way they took 'hundreds of thousands', more like thousands in total. Especially since contactless payments usually have a very low transaction limit (something around R$100 in Brazil).

(Reply depth reached) I guess if you're filtering through a big crowd then indeed you could get really close to people and their wallets. I thought GP was saying you could immediately skim every person in a crowd at once.

Have you been to a Carnival party in Brazil? Most of the time, you won't have "single-digit cm" between you and the next closest to you.