What counts?

I assume that there wasn't some kind of mission impossible stunt to get access to the data. In fact, given the companies are entirely unrelated, it seems likely that the database was accessible over the internet.

So, copying data from one database to another is illegal, however it is done. And this is basically a Top 1000 list. Should Google be worrying right now?

Would Amazon be infringing if I used their database as a purchasing guide, or made myself a "my top 1000 poems" list based on their work?

Saying that, the court cases appear to be going the way you'd hope - the knock-off anthology on CD gets ruled against, but so are the BHB. The airline screenscraping cases will be an interesting test!