15 is probably just 1 scammer, so not big as % of txs, but a big increase from practically non-existant until january 2025. Idk how they track it. My guess is reports from users. But it would be a great question to ask nostr:npub1sqn6rpml88nq8khuvvneuqztfmvalpsarr8grkwy837hzdw63ajs6t5net

Scammers are not tracked, rather it's user reporting having sent money to a seller with 0 reputation and never having heard from him again.