French intelligence has unravelled the messaging app account of the country's most notorious Isil propagandist, leading to almost a dozen arrests in a month, according to reports.
Rachid Kassim, a 29-year-old former child carer, has become France's public enemy number one after being linked to at least two jihadist murders and a string of plots.
Despite his standing in some extremists' eyes, he has come in for harsh criticism from Isil sympathisers for the "amateurism" of his online terror tips, it has emerged.
Kassim has 317 followers via Telegram, an encrypted messaging service, from which he runs a "public jihadist channel" and offers advice on how to carry out attacks in private chats.
He is suspected of "remote controlling" from his Syrian base the failed attempt to blow up a Peugeot packed with gas canisters near Notre Dame cathedral in Paris 10 days ago.
Ines Madani, 19, and three friends were alleged to have followed his instructions to "fill a car with gas cylinders, sprinkle petrol in it and park in a busy street... BOOM".
The women ran off leaving the hazard lights flashing after failing to detonate the gas by setting fire to a rag.
Kassim is alleged to have groomed three boys aged 15 who were arrested this week in the Paris region on suspicion of preparing attacks. One had been planning to stab passers-by, police said. Two teenage girls - also alleged followers - were charged with the same offence last month.
Kassim worked at a child daycare centre in Rouanne, in the Loire, before being radicalised by a local imam.
He was thrown out after trying to brainwash children with jihadist propaganda. He also released a premonitory rap song called Terrorist.
He left for Egypt in 2012 with his wife and her child, and disappeared from the intelligence radar, only to resurface in late 2015 after creating a Facebook page under the false name of Nicole Ambrosia.
Intelligence homed in on his network in June when they linked him to Larossi Abballa, who murdered a police officer and his wife in Paris. He quoted Kassim online before being shot dead by police.
Kassim appeared unmasked for the first time in an Isil video praising Mohamed Lahouaiej-Bouhlel, the Tunisian who killed 86 people in Nice on July 14. He was filmed decapitating a captive while calling on Muslims to commit atrocities in France.
In July Adel Kermiche and Abdel Malik Petitjean, both 19, exchanged messages with Kassim before they slit a priest's throat in Saint-Etienne-du-Rouvray. After murdering Fr Jacques Hamel, 85, they were shot dead by police.
According to Le Monde, French intelligence managed to hack into his Telegram account and decode messages.
It said Kassim calls on followers to launch rudimentary attacks with knives and other weapons.
u?Teachers in Aix-en-Provence, southern France, have been handed "alarm" bracelets to alert police about any security threat amid fears of terror attacks. Some 74 nurseries and primary schools in the town have been equipped with the accessory.