Jack of the crab whom is jackable also know as ' cracker jack'. To be labeled as 'jackable' means you resemble jack as one of the most disrespectful people in the whole world.
A building, fence, object or structure that poses such a risk that it becomes a barrier to entry and requires further brainstorming to find a diversion or incites an unlawful entry.
Jack - that electrified, razor wire, German Shepard patrolled perimeter is definitely not jackable
Other Guy - Watch me and see how it’s done
Jack - *severed by fence spike, entangled in razor wire & watching ear run away in mouth of rabid dog*