The really troubling property from a secret service point of view of this whole system is, that there is no interest in Islamic banking. Thus, you can not derive from the nature of transfers, whether they are business related.

Business related deposits would usually aggregate where the most interest can be gained. Thus unmoving fortunes become "suspicious".

In addition, this system partially prevents the usual corrupt bankers, letting unguarded illegitimate or frozen "fortunes" vanish. There are no courts for dictator money lost during a government upheaval. Of course this is idealizing the thrust-persons.