Given that, it is not surprising that they want a lot of information about your business.
This is an incredible power. The power to effectively drain the bank account of every customer who has ever done business with you.
For credit card transactions the basic mechanism for making a payment is fundamentally equivalent to handing over a signed stack of blank checks to the merchant and having them fill in all the details.
Yes, this highlights how massively broken the system is. However, it also highlights why it's necessary to avoid every Joe on the street having a merchant account.
For check transactions, receipt of one check -- signed or otherwise -- is exactly the same. The information printed on the check is sufficient to print a "demand draft" -- a financial instrument which functions exactly as a check except it is printed by a third party and hence looks different and bears no signature.
Yes, this really does mean that anyone who has ever glanced at one of your checks can knock up a demand draft on any computer with a printer attached, for any amount they desire.
And in the case of EA/Mythic Entertainment / Warhammer Online, this has happened last year http://ireport.cnn.com/docs/DOC-430817
(billing past and present customers multiple times, sometimes incurring huge overdraft fees and leaving some stranded without access to money over a weekend as the banks would block their debit cards)