They were expecting something, and deprioritized/ignored investigations that might have prevented it. I think they were only surprised by the scale of it.
The bigger and more obvious conspiracy was the package of actions they had pre-planned to take advantage of whatever happened (the Patriot Act, the Iraq War).
Hey, could you stop reducing your ad-sales value to my platform? Thanks.
Be the change you want to see in the world, invite a boy to watch The Matrix with you.
I just got an enormous Falung Gong spam, entirely in Chinese, which I do not speak. Usually any spam I get in Chinese is about wholesaleing partnerships.
The real monster in this story is the homeowners' insurance company.
"Chinese imperialism" 
I appreciate the need for its existence, but I could happily go without ever seeing it.
Does the Biden campaign need to do better at reaching out to voters under 35, even if it means abandoning unpopular policies?
No, it's the polls that are wrong.
If they had planted passports, they would have been Iraqi passports. So weirdly, this one part of the story has to be true.