Ok, here is my question. Around here we have two Terminal Control Areas that butt together so when flying over the water to the island you are handed off from one to the other (pretty standard). A few times this summer I have heard on our local ATIS something like this. "Vancouver terminal class C airspace is restricted. Pilots crossing the straight contact Victoria terminal on..." Now I assume you just call up like normal and on you go. My question is what would cause this airspace restriction?