Well, THAT didn't take long
Wire story on Salon: Microsoft .Net security flaw reported. Is this thing even outta beta yet? and already they're finding security flaws? and you can even think for a second of letting these people anywhere near your credit card number? Forget it. The ridiculous thing is that Microsoft could actually use this sort of situation to their advantage, by publicizing their rapid reponse to fixing security holes. Instead, they trot out the tired old "security through obscurity" mode: notice that Microsoft chastises the company for publicizing the exploit instead of "working with them first," i.e. reporting it to MS and then keeping their mouths shut.