Originally Posted by pompousjohn

I am not talking about deliberately allowing fraudulent transactions, I am talking about varying levels of scrutiny. If you had spent the last 5 years poring over transaction details as I have you would know that any anti fraud measures also trip up honest customers who just happen to mess something up. There is an inverse relationship between volume and quality that can be hard to manage.

Pretty much any fraud filter is going to raise false flags. If volume is low and quality is decent, you want to make the checkout process as hassle free as possible. As volume increases, so do your risk factors and security measures have to be put in place, even though these will undoubtedly inconvenience and possibly discourage honest customers: at that point it's worth it to lose a few good ones in order to keep the bad ones out.

It's all very subjective and its easy to go too far in either direction. Too loose and you are a playground for carders. Too tight and you are useless to everyone.