I'll throw my two cents in which isn't worth anything anymore. Pennies are on their way out. I believe this to be a home grown operation. One because of the material used which was very crude. But it's a toss up as to what group did it. Whether it was some wanna be extremists or like the Oklahoma city guy Timothy McVey will remain for the FBI to figure out. But it seems obvious that there was more than one person involved.
And what will this do for our safety and security? Not much really. More laws will be passed limiting our freedoms of movement. More money will be spent on snooping eyes and cameras. Random searches without warrant may become common place. Once again you'll be guilty until proven innocent and the march to a police state will continue. Forget carrying a backpack or large case and don't be caught driving a plain unmarked rental van. " May I see your papers please" just might become common place even though it's not a requirement of the law no matter what they tell you. Police lie more than criminals.
What now for event security? Airport type screenings complete with xray machines and body scanners? Or perhaps you're overdue for your rectal exam. We know someone wants to sell more trans-vaginal probing machines. They must have a powerful lobby in congress.
My flippancy aside the rules will be tightened once again for a time until we fall into the comfort zone of apathy, we do after all have the attention span of a gnat anymore. Do you remember who did the damage in Atlanta when two bombs were set off? (No google look up cheating either) Thought so, you probably forgot what you ate for dinner last night and your car keys are right where you left them. So time will pass and the victims forgotten along with the whole thing until the next horrific event. Have we totally lost our sense of empathy or has this become a part of the new human psyche? We have after all witnessed more carnage of three lifetimes in just the last 12 years. I'll let the media analyze this to death then the conspiracy theorists can take over. Me I have better things to do.