I'm not overly familiar with the law in the United States, but in Australia recent court decisions strongly suggest that it will be more difficult to prove copy

I'm not overly familiar with the law in the United States, but in Australia recent court decisions strongly suggest that it will be more difficult to prove copyright subsists in a database. See particularly the decision in Telstra Corporation Limited v Phone Directories Company Pty Ltd [2010] FCAFC 149 as well as the High Court decision in IceTV Pty Ltd v Nine Network Australia Pty Ltd [2009] HCA 14. The Australian law firm Freehills have a nice write up of the Phone Directories case at http://www.freehills.com.au/6854.aspx http://www.freehills.com.au/6854.aspx. Distinct from copyright, a website owner may have an argument on the basis of contract that scraping data violates the terms of use you agree to when you visit a website. I'm not aware of cases in Australia that deal with the validity of such contracts but this may be something to discuss further with a lawyer.