Pretty sure that when it came to the Superfamily, Luthor was the one enemy they all had on their minds. It was certainly the first one that came to mind for him.

"Robin's probably already got them under surveillance or something. Besides, Batman never really did want us on his turf anyway." Superboy is not about to run out and start talking to the bad guys just because they're behaving.

"Yeah, I heard about the Shade already. Talked to him too."