I've just started using BTC after a few months and I notice that mtgox now requires a photo ID (passport, driver's license, etc) to withdraw any currency to either bank accounts or dwolla. This was never the case in the past when I had used mtgox to exchange BTC to USD. From what it looks like now, all exchanges are mandating this. Is this in fact the case with all exchanges now, and what is the reason for this requirement? It's been a few months since I've used these services, so anybody who could fill me in on this, the information would be very much appreciated.