Secondo il giornale inglese The Telegraph l’intelligence francese avrebbe pre-avvisato le linee aeree sulla possibilità di attacchi ai velivoli tramite l’impiego di razzi anti-carro:

French security forces are bracing for the eventuality of civil unrest and fear there could be a missile strike on a passenger airliner or a September 11-style attack, according to sources close to French intelligence.
“Airlines have been warned of a possible attack on a plane with an anti-tank missile,” a source told The Telegraph. “But pilots are unsure how to take evasive action.”
After Friday’s thwarted attempt to massacre passengers on an Amsterdam-Paris train and a series of terrorist attacks and attempted killings in France this year, President François Hollande warned the nation to prepare for more violence, considered inevitable as the Islamist threat grows. […]

Ovviamente resta da capire se si tratta di informazioni precise e puntuali o se è il ben noto meccanismo di auto-difesa di un apparato di sicurezza in base al quale, soprattutto dopo sospetti fallimenti, “si mettono le mani avanti” rendendo pubbliche anche le informazioni non verificate e generiche. Certo, è preoccupante il fatto che si parli di sistemi d’arma anti-carro. Nell’articolo, infatti, si fa espresso riferimento a quei sistemi che, con la solita e ben nota “lungimiranza” che li contraddistingue, i francesi fornito ai ribelli libici nel 2011 (!!!) e che sarebbero sfuggiti in parte al controllo:

[…] “We don’t know what happened to the arms we (France) to Libyan rebels. It’s worrying,” the source said.
In the chaos following the fall of the Libyan dictator, Muammar Gaddafi, French officials described the north African country as an “open-air arms market”. In 2011, France admitted to sending “light weapons” to Libyan rebels in 2011, but French media reported that consignments of heavier arms, including European-made Milan anti-tank missiles were also sent.
There were fears that Isil, al-Qaeda and other Islamist groups were procuring heavy weapons from the stocks of Gaddafi’s former army, and that rebel groups were losing control of their own arms.
As early as 2010, an anti-tank missile was seized by police along with several tons of cannabis. Since then, an unknown number of rocket-propelled grenades and missiles are believed to have been smuggled into the country.
A missile attack could be devastating for an airliner, particularly if the plane was taking off and full of fuel. The main Paris airport at Roissy is near drug-infested suburbs of the capital prone to violence.
Agents of the DGSI, France’s equivalent of MI5, warned they are powerless to improve surveillance of Islamist militants bent on losing their lives to cause maximum carnage, and have been “lucky” to have avoided far worse catastrophes since the Paris Islamist attacks in January that killed 17, Le Canard Enchaîné, the investigative and satirical weekly, reported.

Ma l’articolo è interessante anche per un altro passaggio laddove si afferma che l’Esercito avrebbe preparato dei piani di contingenza per riprendere il controllo di vaste aree metropolitane (le banlieue?) a rischio di rivolta popolare:

The army has made contingency plans for the “reappropriation of national territory”, meaning to win back control of neighbourhoods where the population become hostile to the security forces and where guns are easily obtainable, according to the source.
“There are a lot of alienated and angry fourth-generation immigrant kids in the suburbs and the prospect of radicalisation is increasingly likely,” the source said.
“The idea that attacks like the one on the train are carried out by individuals acting on their own is not credible. We’re dealing with highly-organised networks of militant Islamists embarked on a campaign of violence and determined to intensify it.”