It's certainly immoral, as are all assaults launched with the knowledge that innocent civilians will be killed. This is why war is immoral, and the way we wage it particularly so. The rationale that "To kill this bad guy, we're going to have to kill 50 good guys, but we're still the good guys" is beyond idiotic, it's monstrous.
Illegal? I don't know. Probably not its use in Afghanistan, but using them in Pakistan and Yemen and in any other nation with which we're engaged in an undeclared war, occupation, or bombing campaign, certainly.
Illegal? I don't know. Probably not its use in Afghanistan, but using them in Pakistan and Yemen and in any other nation with which we're engaged in an undeclared war, occupation, or bombing campaign, certainly.