Obscure screw added so appliance cannot be disassembled
Basic blender went bad (motor ran but spindle wasn't rotating). I wanted to disassemble to see if it could be repaired. Three of the four screws were Phillips head. I had to cut the casing open in order to discover why I couldn't unscrew the fourth. It was a slotted spanner.
My vacuum cleaner. You know how the roller brush gets all tangled up with hair and threads and whatnot, and the way you fix that is to remove the roller and cut it all out?
The external screws are torx security bits. The internal screws are Phillips. The only reason is to get someone who isn't persistent to go buy a new vacuum cleaner when their roller gets tangled