Well the thing is, it's already illegal yet they risked by engaging on it and they should know the consequences through it. I think money laundering was the main case here and the Bitcoin p2p was just the thing they use. Those who know what Bitcoin is knows well that it was just used as an instrument but for some people that still lacking that knowledge might attribute Bitcoin as scam and that saddens me tbh.
they probably thought they'll never get caught which is true some time for small and individual traders. thousands of people in bangladesh are trading bitcoin without any issue.
but these are not normal traders they are a Gang of traders and probably also involved in money laundering.