These programs use different structures, files and naming conventions for the data that investigators are after. And files are in a different location on the hard drive, which can cause trouble for examiners.
You mean that professional forensics specialist might have to learn to deal with more than one browser and actually have to search on the hard drive a bit instead of using a point-and-click program? Shocking!
Imagine what they would think if they had to search my computer (which runs Linux)!
>> Based on my discussions with a FBI computer forensics expert a couple of years ago, this article is over exaggerating the difficulty by several orders of magnitude.
I agree. It all depends how bad they want you. Personally I ERASE permanently (Gutman method) my cache daily. Nothing illegal, just it's no one's business to know what sites I visit and what I do. It's that simple.
I paid about $50 for the eraser and will not use any browser that my eraser doesn't support (Opera 8.0+ is one of them for now).
Safari has a "Reset Safari..." command in the main menu, which:
... erases your browsing history, empties the cache, clears the Downloads window, and removes cookies. It also removes any saved names and passwords or other AutoFill text and clears Google search entries.