Found it.
http://pastebin.com/rP1dWEWZ
Not only have my suspicions been confirmed, but we can all enjoy the realization that the guy making this mod not only is dumb enough to try this sort of enforcement, but also to think the tag "BuildCraft" is going to catch the various chunks of BuildCraft, which are tagged things like "BuildCraft|Energy" and the like.
I also kind of like how he added almost all my mods at once near the end, presumably in some sort of "OMG this guy has like 10 mods" panic.
Not surprisingly, this moron's other three mods - "Slower Redstone", "Mob Buff", and "Double Diamonds" also contain this code in their preload phase.
@
Prodrone
What your admin's friend is doing is incredibly stupid and very much against the rules. Mind feeding them to the dragon?