Copyright law generally allows copying for research purposes that don't compete commercially with the author's use of the work. For example, see https://w2.eff.org/IP/DMCA/Felten_v_RIAA/ (And Google, unlike some of us, can afford lawyers to press that point in court if anyone tries to sue them.)

I can't cite law, but there must be implicit permission for download if your SWF is up on a public site. Otherwise everyone could sue everyone for it.

And once you have the data, I'm sure there are very few, if any, restrictions on how you process it internally.

Redistribution is another matter, but Google doesn't seem to have done any of that.

Agreed, awesome.