It's been years since I've seen it, but I remember a hilarious scene where Jack Bristow is talking to someone in an IM-like window; his choice of text is giant red Comic Sans and his messages are devoid of grammar and punctuation.
You could argue that this is typical of the average IM user in the early 2000s, but it seemed incongruous for the character.
You could argue that this is typical of the average IM user in the early 2000s, but it seemed incongruous for the character.