Warning, I was on lunamine until this morning when I finally removed the sig from their sig campaign a couple days after the period ended. They have not paid and claimed they are being hacked and blackmailed right now. I'm owed .048 BTC and there are tens of others owed but lunamine is nowhere to be seen.
Uh-oh!
You know, this brings up a good point which is that it could be very valuable for signature advertizers to demand escrow even from someone with a trusted account who has paid in the past. In this case, if lunamine is really hacked (I have no way to know if it's true or not) then they might not be able to get money to pay their contractees. However, if they had paid to an escrow at the beginning of the term, the contractees would be satisified no matter what happens to lunamine.