The OP has brought this idea up before, several times in other threads. It always gets the same universal response. Why they have felt the need to start a thread I don't know. They know the answer as it's given everytime they mention it.
How the IRA ever managed without Twitter I'll never know.
This is just government scaremongering to justify their fascist motions to invade privacy. Annoyingly for no real reason than they just like to know more about us.
If anything social media is a help to the authorities trying to track and imprison terrorists as it flags them up and provides a clear evidence trail for prosecutions. I suspect the OP is perhaps something of an older gent?