LAS VEGAS -- It used to be easy for U.S. Bank to determine which users and systems could be trusted, and which should be viewed with suspicion. Then along came Web 2.0. 

"We always said outside the corporation was untrusted and inside the corporation was trusted territory," U.S. Bank CTO Gary Hodge said in a keynote panel discussion on Web 2.0 security at Interop Las Vegas Wednesday. "Web 2.0 has changed all that. We've had to expose the internal workings of the corporation. There's a whole rash of new devices coming out to enable people to compute when they want to, with the iPhones and smartphones."

At the sixth-largest bank in the country, Hodge is worried. While it took a decade or more to gain a "level of hygiene" in PCs, with virus scanning and other security tools, he thinks smartphone developers haven't paid enough attention to security. (Compare security products.) 

"I don't think most people have thought about their smartphone in that context," he said. "There's probably a whole rash of vulnerabilities that will show up in the next few years, and we're not sure what they're going to look like."

Hodge was joined by Gary Dobbins, director of information security at the University of Notre Dame, and two officials from the vendor Secure Computing. 

Secure Computing sees more than 10,000 malware samples a day, and they are growing in sophistication as organized crime and terrorists utilize the Web for malicious purposes, said Dmitri Alperovitch, principal research scientist for Secure Computing.

"The potential from a criminal perspective has expanded dramatically in the last several years," Alperovitch said. "It's no longer about someone breaking into a computer and hacking your Web site. It's much, much more serious."

There are two main problems, according to Alperovitch. Content in the Web 2.0 world can be produced by any individual who comes to your Web page, particularly social networking sites. Secondly, the browser is now the operating system, providing access to instant messaging, Web conferencing, telephony and any other number of services. The security perimeter is shrinking, Alperovitch said.

The advice from Dobbins is simple: "Never trust the browser," he said. "It's amazing how many sharp programmers will make that mistake."