http://news.yahoo.com/exclusive-expert-warn-congress-healthcare-gov-security-bugs-144729835–sector.html
I think the following line about sums it up:
“They said HealthCare.gov runs on 500 million lines of code, or 25 times the size of Facebook, one of the world’s busiest sites.”
With spaghetti code like that, it’s no wonder that it’s hard to defend. The real wonder is that they still don’t want to take it down even knowing some of the vulnerabilities have been made public, and at the suggestion of 3/4’ths of the experts involved.