Mark writes:

Well I certainly have. How do I know this? Because I've
been in groups and the key members said, "Hey folks,
we're all going to face book. Then they did."

I haven't seen that in any of the groups I frequent.

I'd think the five hundred million people membership alone
would squelch any pan flashes.

The number of subscribers does not limit the speed with which they can all
move to something else.