I cannot think of a better way for this group to hurt their cause and garner the animosity of much of the world. It seems to endlessly repeat throughout history- groups with an axe to grind (whether in power or rebelling against it) use blunt force to try and further their cause. They're either too lazy or not competent enough to use a scalpel so they blow up the patient to get rid of a tumor. After the majority of t…
Or it's an opposing group using its name to discredit it.
It's easier to benefit from a false-flag attack by just doing it- denials don't carry as much weight in an emotional, post-attack context. When forewarning is given for a false-flag, you give the accused a chance to back away and say "it's not us" before an event, lodging enough doubt that the size of the crowd with torches and pitchforks isn't as big afterwards... I think this would be counter-productive for the guys staging the false-flag attack.