If your notebook is filled with porn, P2P or even just too many iTunes downloads, you might want to think twice before taking it on your next holiday -- especially to the US.
An appeals court in California this week unanimously upheld a ruling that border security officers at international airports can search personal computers without requiring any specific evidence of criminal activity. The appeal was made by a US resident, Michael Timothy Arnold, charged with child pornography offences after an airport search of his notebook PC in 2005.
Searching of people or property without a warrant or reasonable grounds for suspicion is generally forbidden under US law, but that ruling doesn't apply at border locations such as airports. (A side fact from the judgement you quite possibly don't want to know: one of the few restrictions in this area relates to searches of the "alimentary canal".)
"We are satisfied that reasonable suspicion is not needed for customs officials to search a laptop or other personal electronic storage devices at the border," Judge Diarmuid F. O'Scannlain wrote in the ruling.
So what does that mean in practice? Don't have anything on your computer that you wouldn't be prepared for a border security official to examine if you're heading stateside. Given that Australia and the US have broadly synchronised copyright laws, one area to think about is downloaded TV shows and movies.
Although we can't imagine that immigration officials want to spend all their time checking for illicit episodes of Lost, there's seemingly no legal reason why they can't. If you happen to have pictures of alimentary canals being used for sexual purposes, those might also be better left at home.
Apart from the possibility of a pirate TV customs bust, travellers returning to Australia need to take some other issues into account as well. There's a $900 limit on what Australians can bring into the country before duty may be payable. If you have a particularly new and shiny machine, take the receipt with you so you can prove you didn't buy it overseas.
Physical objects aside, as digital content becomes more common, it would be entirely possible to exceed this limit with content purchased legitimately from overseas locations (such as the common routine of purchasing iTunes gift cards to get access to songs not released in the local version of Apple's music store). While spending $900 on songs might seem excessive, if you have done that, you should declare it -- or stick to what you can acquire at home.