"there are no identifiable "Islamist communities" in Britain" (21 Jun 13 - 04:38 AM)
That was you Jim, and I disagree.
You might prefer to call them groups. organisations, followings, gangs, etc. but they exist.

"Yes there are. MI5 and the police are aware of many." (21 Jun 13 - 05:08 AM)
That was me.
It is a reasonable statement.

"No there aren't " (21 Jun 13 - 10:18 AM)
That was your unsupported and silly statement.

"MI5 knows of "thousands." What is the lower limit for a community Jim?"   (21 Jun 13 - 10:42 AM)

Yes, it knows of thousands of Islamists, so how many do you need for a community?

I have never linked the words "thousands" and "communities"