Yamihimitsuno,

At first this stumped me a bit, but I think I may have one possible non-paranormal solution.

I don't know what the place is, of course, but regardless of that, it sounds like the kind of place bored teenagers might try to explore for kicks, especially if it's out in the boonies. If that's the case, maybe they figured "Well if we put the barbed wire facing in, then those damn kids may still be able to get over the fence to get in, but they won't be able to easily get out and we'll soon have the cops on the situation." (either by the kids having tripped an alarm, a neighbor possibly hearing/seeing a commotion by this electrical station or whatever it is, or just the teens still being corralled in like cattle, come morning). Or even if the kids DID get out, they might not do so in time, prior to the cops arriving. At the very least, they'd tear up their hands and so forth, and would probably think twice before doing it again, or recommending it to their friends.

Anyway, that's my thought.