Buffy's expression changed dramatically. She may not have had a potty mouth, but she had plenty of spark and fire to go around.
"Are you insane? Spike is a killer. How exactly do you plan on keeping track? You can't exactly put a leash on him. Unless you're from the government. You're not from the government, are you? Because that whole chip thing didn't exactly last..."
Buffy was all about helping Spike. She just wasn't exactly about helping the demon side of him.