Yeah there is an under used IDE feature which allows you to password protect a drive essentially at the hardware level.

That's what the XBOX uses to encrypt it's harddrives.

From memory when I looked at the IDE spec it was possible to remove the password at the expense of the data on it....

From the ATA spec.

"If the User password sent to the device with the SECURITY UNLOCK command does not match the user
password previously set with the SECURITY SET PASSWORD command, the device shall not allow the
user to access data.
If the Security Level was set to High during the last SECURITY SET PASSWORD command, the device shall
unlock if the Master password is received.
If the Security Level was set to Maximum during the last SECURITY SET PASSWORD command, the device
shall not unlock if the Master password is received. The SECURITY ERASE UNIT command shall erase all
user data and unlock the device if the Master password matches the last Master password previously set
with the SECURITY SET PASSWORD command."

So as long as the drive is only set to high security you can probably send an erase command to it (master password probably isn't set). If it has been set to maximum security you're possibly stuffed. A low level format might get you out of trouble.

You need a program that can send any harddrive command. Mark Lord might be able to help - I'm unaware of a program, linux or Windows that will let you control a drive at this low level.