After re-watching the incident it was clear to me that when Ilana found the cabin and said "he hasn't been here in a long time" she was most definitely referring to Jacob.
When she said "someone else has been using it" i believe the person using it was christian shephard, aka blackshirt.
I think that Jacob used the cabin as a place to safely communicate with whoever he needed to at the time. He has always lived in the statue but I am not sure that blackshirt knew that. The only person who knew where Jacob lived was Richard.
The ring around the cabin was to ensure that blackshirt could not use the cabin himself, or fool someone for that matter.
Here's my theory as to who breaks the ash. I am quite certain that Charles Widmore breaks the ash a little bit before the purge. If Jacob was all about bringing people to the island, then he definitely brought the dharma initiative to the island, and is it possible that it was Jacob himself that built the lampost? This would explain why the others have a truse with the dharma initiative and let them live on the island, because Jacob needs them there to build the swan, so that the incident can happen and send the losties back to 2007, so they can win the war against blackshirt. This would also explain why they allow the swan to be built on hostile territory.
So this brings me to Charles Widmore breaking the ash. I think like Ben Charles becomes tired of being in the dark, never meeting Jacob and always answering to Richard. So he secretly follows Richard to the Cabin and sees them converse. He notices the ash and may understand why its there. Because at this point Widmore is so tired of the dharma initiatve, has become tired of richard, and has now become a greedy leader who wants the island to himself, he breaks the ash knowing that he may be able to communicate with the opposing side to the island. Widmores first task from blackshirt is to rid rousseau and baby alex. Widmores next instructions are to convince ben to lead the purge and kill off the dharma initiatve (think blackshirt wanting to rid the island of everyone. from there we eventually see blackshirt use the cabin to trick locke into turning the wheel and dying.
When she said "someone else has been using it" i believe the person using it was christian shephard, aka blackshirt.
I think that Jacob used the cabin as a place to safely communicate with whoever he needed to at the time. He has always lived in the statue but I am not sure that blackshirt knew that. The only person who knew where Jacob lived was Richard.
The ring around the cabin was to ensure that blackshirt could not use the cabin himself, or fool someone for that matter.
Here's my theory as to who breaks the ash. I am quite certain that Charles Widmore breaks the ash a little bit before the purge. If Jacob was all about bringing people to the island, then he definitely brought the dharma initiative to the island, and is it possible that it was Jacob himself that built the lampost? This would explain why the others have a truse with the dharma initiative and let them live on the island, because Jacob needs them there to build the swan, so that the incident can happen and send the losties back to 2007, so they can win the war against blackshirt. This would also explain why they allow the swan to be built on hostile territory.
So this brings me to Charles Widmore breaking the ash. I think like Ben Charles becomes tired of being in the dark, never meeting Jacob and always answering to Richard. So he secretly follows Richard to the Cabin and sees them converse. He notices the ash and may understand why its there. Because at this point Widmore is so tired of the dharma initiatve, has become tired of richard, and has now become a greedy leader who wants the island to himself, he breaks the ash knowing that he may be able to communicate with the opposing side to the island. Widmores first task from blackshirt is to rid rousseau and baby alex. Widmores next instructions are to convince ben to lead the purge and kill off the dharma initiatve (think blackshirt wanting to rid the island of everyone. from there we eventually see blackshirt use the cabin to trick locke into turning the wheel and dying.
