Compared to putting a frag grenade in the cup of your water bottle and attaching some string to the grenade's pin as a trigger - a rather sophisticated method Hunter.
But I doubt the cardboard box will contain any kind of explosion. Back to topic: I would rather approve if the existing traps would actually kill people since I was told they just explode without doing any damage. Actually any kind of booby trap would work as an IED Andrew, I guess it's just the name that changed. And the sophistication. Whilst booby traps work mostly mechanical you need at least a small amount of electronics for an IED because the most common type remotely triggers the detonator cap of i.e. a mortar round. I guess that could work with a HE 203 as well so the materials would rather be scrap electronics, some kind of wire and the HE round. Or satchel charge. Oh, and duct tape. You always need duct tape for building explosives.