> you realize if you piss off anyone doing this, they can have you sent to jail right?
Are you talking about Aaron Swartz? There were complicating factors. Typically, no, scraping is not a criminal matter. If you need a lawyer, however, you should talk to one.
> Automated scraping is unlikely to qualify as fair use in court.
Scraping is not [usually] the problem. It is what you do with the scraped content that is the problem. Additionally, the nature of the scraped content itself is at issue: facts are not copyrightable, for instance, just particular expressions.
Fair use is a hugely, hugely complex topic. If you ever ask someone if something is fair use and they give you a straight "yes" or "no" answer - don't trust it unless they are also showing you a court decision that covers your exact scenario and is valid in your jurisdiction. Any good answer will include a healthy does of "it depends."
The only way to conclusively determine if something is fair use is going through the fair use "run-time" - which is a court decision on the topic. There is no other way - none - to determine if something is fair use and claims to the contrary are false. To be clear: fair use is a judicial determination and it is highly fact specific.
Disclaimer: I am a lawyer, but I am not your lawyer. If you need one, you should get one.
As far as I know, only Japan has laws.that allow scraping without explicit permission.