there's a few of us. you have a different symbol...

[Whatever that means. Maybe there's a difference after all? He couldn't tell you what it is, though, honestly straight-up deduction isn't his strongest suit. So he's thinking aloud:]

it's hard to tell what they're testing. how people will react to having their answers to a question like that posted in public? how people will deal with an app that acts like a virus? both?