From what I learned today, they've been aware of these guys, but pretending they had no idea they were there so they could study them (and probably feed them bogus data). My guess is they are SIGINT platforms, monitoring our microwave traffic.

We have been pretending complete ignorance of them, but had to do something once that jackass in Montana put his pictures on the internet. As for shooting it down over the ocean, my guess is they don't want the Chinese to know just how much of it was recovered. Did you see how quickly the shoot-down was organized, and the recovery team deployed? Even if they fail to find any useful intelligence in the wreckage, the Chinese will have to assume the whole program is now compromised.

And of course, we are making political hay out of this, with the Sec of State pouting around like a bridegroom spurned at the altar. The Chinese were congratulating themselves for humiliating us, now I bet the people in charge of their balloon program are answering some very tough questions in Beijing.