pro-palestinian groups and groups that oppose "islamophobia" don't strike me as likely vectors of violence, even if i broadly find them annoying and don't like them. targeting muslimy groups that don't have anything to do with the actual problem is both likely to lead to a counter-movement and ultimately have no effect in resolving the actual problem.
this guy seemed to just be a local crazy, and if there was a breakdown in safety, it was probably due to poor screening measures when he was let into the country as a refugee. if there's anything to be done by the state, it would be in stricter screening of refugees from particular regions for particular viewpoints. a values test might be stretching it, but a few poignant questions like "would you kill a person that offends you?" are likely useful. you could even present them with a picture of mohummad and see how they react.
but, the root cause is really in the mosques, themselves, and the way to neutralize the problem is through greater integration, not through further ostracism. these people need to somehow be convinced to become apostates, and isolating them further is going to do the opposite - it's going to harden them, and deepen their delusions.
there's a good opportunity here for a meaningful dialogue, but mr. macron seems to want to institute a reign of terror that will boost his popularity, instead. that's unfortunate.
there are certain groups that need to be wiped out with force but, broadly speaking, the way to eliminate islam is to convince muslims to abandon it, and these decisions seem to be moving in the wrong direction.
i hope the french republic can see through this and pick the proper middle point in both denouncing radicalism and prioritizing coercive integration as the proper path to secularizing immigrants.