"'A very particular set of skills I have acquired over a long career, a set of skills that make me a nightmare for people like you. But if you don't, I will look for you, I will find you. And I will kill you.'" Dinah recited with a bit of a grin-- though it didn't look like Agent Coulson had ever seen Taken.
Canary didn't know how this guy knew about her sonic scream, though it wasn't actually a well-kept secret or anything; it just always put her on edge when people knew things about her before she'd ever met them. That was part of the job though-- once Bad Guys knew what you could do, it usually made them less likely to want to mess with you. "Look, Agent Coulson, let me just save you some trouble. I really appreciate the compliment but I'm not interested. You should definitely see the sites while you're in Gotham though. No sense in making it an entirely wasted trip."