He keeps a log
They both leave kid's homes with empty sacks.
He knows where all the naughty girls live. I actually heard this in the video game LA Noire. Thought it was pretty funny so I bust it out every Christmas.
Guy: I don't remember.
Lettuce alone, without dressing. I remembered this today from a joke book I had when I was a kid. Wasn't sure if it should be here or /r/dadjokes
They log on.
Logs on to Wikipedia*
Black mail!