Yep, look at Hong Kong.An unarmed populous is far easier to quarantine...what are they gonna do? Throw rocks? And yes, in those numbers they could easily overpower any traditional ground force barricade....but many would have to be willing to die to do that. A populous kept as sheep, treated like sheep, and happy to be sheep...will not consider the sacrifice as worth while...
Till the water stops flowing and the food runs out.