From Sky News:
Thousands of documents detailing phone numbers and family contacts are handed to Sky News by a disillusioned convert to the group.
Tens of thousands of documents, containing 22,000 names, addresses, telephone numbers and family contacts of Islamic State jihadis, have been obtained by Sky News.Nationals from at least 51 countries, including the UK, had to give up their most personal information as they joined the terror organisation.
Only when the 23-question form was filled in were they inducted into IS.
A lot of the names and their new Islamic State names on the registration forms are well known.
Abdel Bary, a 26-year-old from London joined in 2013 after visiting Libya, Egypt and Turkey.
He is designated as a fighter but is better known in the UK as a rap artist.
His whereabouts are unknown.
Another jihadi named in the documents, now dead after being targeted in a drone strike, is Junaid Hussain, the head of Islamic State's media wing who along with his wife former punk Sally Jones, plotted attacks in the UK.Re the Yazidis:
Her whereabouts are unknown.
Reyaad Khan from Cardiff, who also entered in 2013, is also among those found among the registration forms.
He was well known for appearing in a highly produced Islamic State propaganda video.
He was later killed.
But the key breakthrough from the documents is the revealing of the identities of a number of previously unknown jihadis in the UK, across northern Europe, much of the Middle East and North Africa, as well as in the United States and Canada....MORE
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Those women could probably figure out a use for the information.