Smokey is Chained To The Island by daveleclair

I always wondered why the Smoke Monster couldn't just hop over the Dharma sound barrier. Doesn't it seem like he can fly? Upon further thought - NO. He's grounded on the island and can't leave its earth.

A few times we see him appear from minor eruptions in the ground, and he tried dragging Locke down a hole at the end of season 1. We always hear a rattling chain-like noise as he moves around. While it seems he can levitate and fly, we never see his tail end like this - only the leading head part of the smoke. The Smoke Monster is definitely "chained" to the island. Now, he *may* be able to project himself off-island in other forms, but he himself cannot leave. I also want to note that he would not be able to fly to the top of the lighthouse. Before Flocke, we saw he couldn't physically do things on his own which is why he couldn't get through the locked door. (That is, if he could see the lighthouse at all!)

What's the significance? We'll see more as the season develops. The first thing is that when Flocke said he's "trapped", he was telling the truth. The second thing is, being stuck to the island's earth has a lot of implications around how dead bodies are handled by The Others and how they can become zombified.