Hardware Freedom Day Apr 20, 2013

Shall we do something for hardware freedom day? http://www.hfday.org/
I'm open to ideas but here is one:
In the spirit of april fools: An ice-cream protector -- this is a fake pint of ice cream (think Ben and Jerry's) and when the ice cream "thief" takes off the lid a piezo siren goes off! Or what else? A cell phone vibration motor? Can we use an accelerometer to trigger if its touched? Can all the electronics be packed against the lid so a real (and full) pint can be protected?