So why can't everyone just claim they forgot their password? Additionally, what stops you from setting up some kind of hard drive degausser inside your case that is set to go off if the case is moved? Would you be responsible if the police officer removing your computer from your home inadvertently set off the degausser?
Not if you had it setup prior to any sort of court order to degauss the drive regardless of who tampers with your system or why. For example, Coca-cola might do that on a manufacturing system that controls the quantities and timing of the raw ingredients to produce the formula and is evidence only that they want to protect it. However, once the court has ordered you to turn over your system as evidence, you can't simply point and say "Sure, it's over there... take it" knowing full well that it will get wiped as soon as it's moved. That would be destruction of evidence.
I am not a lawyer. This type of device can have legitimate use as well though. Think about if you are the guy that knows the coca-cola recipe. The destruction of the recipe by hd degaussing is good when a competitor comes to your office and steals your computer. Though, you would need a pretty large degaussing device to erase the hd beyond forensic analysis.
Absolutely not. As another poster pointed out, if it predated the court order, it would be 100% legit. Say I wanted to make sure my data was safe in the event of theft? Wiping the data on movement would be a clear way to do that.
I thought about that, but wouldn't it only be destruction of evidence if YOU were the one that destroyed the evidence? Just because it was set off when the cop/FBI/whomever moved your computer doesn't mean you wanted it to happen, right?