There's been a lot of attention paid recently to the issue of laptop searches at borders, including a congressional hearing and a New York Times editorial. I've seen articles with advice on how to protect your data under such circumstances; generally speaking, the advice boils down to "delete what you can, encrypt the rest, hope that Customs officials don't compel production of your key, and securely clean up the deleted files". If you need sensitive information while you're traveling, the usual suggestion is to download it over a secure connection, per the EFF:
Another option is to bring a clean laptop and get the information you need over the internet once you arrive at your destination, send your work product back, and then delete the data before returning to the United States. Historically, the Foreign Intelligence Surveillance Act (FISA) generally prohibited warrantless interception of this information exchange. However, the Protect America Act amended FISA so that surveillance of people reasonably believed to be located outside the United States no longer requires a warrant. Your email or telnet session can now be intercepted without a warrant. If all you are concerned about is keeping border agents from rummaging through your revealing vacation photos, you may not care. If you are dealing with trade secrets or confidential client data, an encrypted VPN is a better solution.
But is it?