Well as we all know that whenever we transact it always go through blockchain first. So is it possible that blockchain can detect illegal trasanction such as buying drugs, guns, hitman etc., especially on deepweb. And where does bitcoin go when blockchain detects a illegal transaction?
block chain don't know which transaction being done for an illegal purchase or deal. all transaction are same.. block chain can't detect transactions. but if we know an address of a scam person and report about it in blockchain, then may be blockchain can cancel transaction to this address.