At first I believed it was indeed a bot, but after playing with it, I've concluded that a bot is indeed present on and off, but the interactions are with other anonymous users. Reasoning? Here's some quotes, at least, the ones where I don't curse and get all NC-17 -
User: So, Twilight sucks, doesn't it?
Cleverbot: Sure it does.
User: Smoke crack and worship Satan.
Cleverbot: I don't smoke, and I don't have any cigarettes.
User: So you would worship Satan?
Cleverbot: You're disturbed.
Cleverbot: You unlock this door with the key of imagination.
User: I want to unlock pants with a key of something else.
Cleverbot: How do you do that?
User: Working on it. Probably invovles string theory, and a lot of alcohol.
Cleverbot: Very probably.
User: The bot is a lie.
Cleverbot: In Soviet Russia Bot's Type you.
Cleverbot: Are you a boy or girl??
User: I'm a boy. Are you a girl?
User: Wanna make out?
As I said, the bot is present, but the users are human. Every few lines they will change, so you can't have an actual conversation. Other than me, this place has been pretty family friendly all night, and once I had an inkling that it might be kids rather than a machine, I toned it way down. But either way, play with it if you want - and don't blame me for what people say on there. I cannot post my initial chatlog, but I'm sure you have an idea of how it went.