Take this Offline”

Twice in the past month, once in a meeting and once in a telephone conference call, someone has used the phrase “let’s take this offline.”

By which they’ve meant “let’s not talk about this now, let’s talk about this later.”

But the phrase makes no sense to me: if we’re discussing something face-to-face (or telephone receiver to telephone receiver), we’re already offline, aren’t we?

Maybe I’m interpreting this too literally, but it gets even more confusing when you realize that when people say “let’s take this offline,” they often mean “let’s exchange some email about this after the meeting.”

In other words what they really mean is “let’s take this online.”

Am I missing something?