Safari 4's Messy Trail
Signum Ignitum writes "Safari 4 comes with a slew of cool new features, but extensive data generation combined with poor cleanup make for a data trail that's a privacy nightmare. Hidden files with screenshots of your history, files that point back to Web pages you've visited and cleared from your history, and thousands of XML files that track the changes in the pages in your Top Sites can add up to gigabytes of information you didn't know was kept about you." Some of Safari's bloat is kept in quite obscure locations; it takes a fairly knowledgeable user to find it and clean it up. You can avoid some of the worst of it by disabling Top Sites.
There is a "Empty Cache" button under the "Safari" menu.
Before "Empty Cache"
ahze:/private/var/folders/zz/zzzivhrRnAmviuee++31gU+-Ev6/-Caches-/com.apple.Safari ahze$ du -sh
129M .
After "Empty Cache"
ahze:/private/var/folders/zz/zzzivhrRnAmviuee++31gU+-Ev6/-Caches-/com.apple.Safari ahze$ du -sh
32K .
The real scary part of this for me is not the government, more on that in a sec, but your girlfriend/boyfriend/housemate. Anyone who feels like he/she wants to do some snooping now has a treasure chest of stuff to take out of context.
I hope no one here is naive enough to use the "if you have nothing to hide..." line.
Getting back to the government, most cases are not high profile law&order style procedural deals. I could easily see local lawyers taking porn sites as evidence you killed her, technology sites as evidence you were researching bombs, map sites that you were researching crimes, and I can see local judges allowing it, and local jury's believing it.
Of course they could get most of this from ISP logs, but that would be just that much harder to get, and wouldn't come with screen shots.