I think it depends on the registrar, some don't bother with it. One thing to note though, is that once you own it, it's difficult for someone to dispute it. They have to pay $700 to file a claim and then even if they prove you have no legitimate connection to the US, you're still given time to create a legitimate connection... If you fail at that, then the domain drops back into circulation. The original claimant and the one who paid $700 does NOT get the domain, so why would anyone ever file a claim?