Determining an acceptable level of collateral damage is a very, very tricky problem. In the Snowden case I think the damage that was done is acceptable in order

Determining an acceptable level of collateral damage is a very, very tricky problem. In the Snowden case I think the damage that was done is acceptable in order to root out illegal activity, but that doesn't mean that collateral damage wasn't done, or that perhaps steps could have been taken to minimize that damage. But ultimately, the calculus for what is acceptable when it comes to collateral damage is extraordinarily subjective. I don't know of any concrete way to judge it so I am usually forced into using my own value system as to what is important in my life.