I would take a page from NodeReaper's book. She's really good at this kind of stuff. A possible script would be something like this.

devon22:
Sneaks up behind user and STAGE-WHISPERS
Are you logged on?

user:
Feigns SURPRISE
Whoa! As a matter of fact, I am. Why do you ask?

devon22:
(Sneaks rope from behind back)
No reason....
(Throws rope over user)
You're captured! I 0wnz you!