Sorry your accounts didn't get approved immediately. Unfortunately abuse of stolen credit cards and other forged documents is a real issue that hurts many people, and businesses.
DreamHost uses an automated approval system that looks at many characteristics of an account before it is approved. These are things as simple as the credit card matching the country of origin of the account holder, and more advanced heuristics. Should any of those characteristics look abnormal based on our historical data, the account is flagged for manual approval.
We try to keep the time for manual approval as short as possible to put you online as quickly as possible but sometimes the queue get longer (because abusers get more and more sophisticated, just like spammers) and we miss a beat or two. Our Abuse team is always improving our tools though.