Could it be something bigger than this? Kind of a global network of fraud or scammer? If it is about money laundering globally, I think it may be done structurally and generally. Respect for all the police that can reveal this kind of criminals. As we know, fraud/scammer systems are commonly very complicated to reveal. And if they are arrested under the law, the police can also reveal more to the people related to them.
I sometimes sell BTC in local market through the help of some facebook group. I never felt that I am in risk but for the first time, it seems like we are actually risking ourself a lot of by selling BTC to unknown. What if they get a trace of ourself and link us with such transactions? Would we be also get punished? For your info, we had to use our mobile number to continue dealing.
Of course, they can reveal more people in relation with them. And if they can track you, do you have any evidence that proves that you are only selling BTC to someone on Facebook? If you have it, you may not worry about it because you may be excluded as fraud systems.
I forgot to mention that BTC itself is illegal in our country which is the major reason of my fear. I sometimes sold BTC to unknown guy and that's what I'm fearing of. If it was legal, I would have nothing to fear at all.
It depends on what kind of law in your country about using Bitcoin. I think that many people in your country actually have been involved with crypto and your government have known about it. I cannot decide what kind of punishment they will give. But, as long as you use it not for criminals and you can prove it, you may be safe. Pray for it.