French and Belgian intelligence knew Paris attackers had jihadi backgrounds

With every new piece of information that has come to light about the perpetrators of the Paris attacks, it has become clearer that the intelligence services in France and Belgium knew about their jihadi backgrounds.
Several had dossiers identifying them as radicals. At least five had travelled to fight in Syria and returned to homes in France or Belgium. They were dots on the radar screen but the security services failed to join them up and so overlooked the gathering conspiracy.
“What we know is that most of these people came back from Syria and nobody stopped them,” said Natalie Goulet, a member of the French senate foreign and defence committee. “Whatever the reform that has been implemented [in the intelligence agencies] it’s not working.”