From Walsall, a small city in the West Midlands and edited slightly:
...police only discovered the group after Rev Petty contacted the police after her son Jacob disappeared in the summer of 2014 and emailed his parents to say he was off to start a “new life” in Syria.
A senior West Midlands Police officer said:
The case here emerged from worried parents about their son who they reported missing. That was Jacob Petty. It turns out he had gone to Syria and joined Isis and from the inquiries we followed, it became a wider investigation and we were able to then open up these evidential routes into all of these people.
Link:http://www.telegraph.co.uk/news/ukne...upporters.html

Background on the network today, from two sources:http://www.telegraph.co.uk/news/ukne...-fanatics.html and the BBC:http://www.bbc.co.uk/news/uk-35653366