Paris Olympics (General)
It is curious given the sophisticated, well-planned, seemingly professional nature of the job done. Note that they could have chosen to kill many people, but they didn't, which is why some argue it wasn't Islamic extremists.
So, yeah, who did it and why? You'd think if it were to make a political statement (i.e., environmentalist), they'd announce it. Was it a test? A distraction from something else?