At Roundtable Corp., which runs some 46 Dairy Queen restaurants across the southwest U.S., the IT department has blocked everything but the company's internal pages and sites that offer weather reports.

The reasoning behind the draconian level of control is a matter of simple economics, said Mike Stump, the company's IT director.

"Our biggest problem was that people were going to sites and downloading all sorts of  shareware and spyware that was effectively killing our machines, which is a big deal because the computers in our store offices are connected to our point-of-sale systems, so these attacks were actually effecting our registers, which was obviously a huge operational issue," Stump said.

Using technology from ScanSafe, which offers hosted applications control tools, Roundtable blocked access and immediately saw its malware problems disappear, Stump said, which also lowered the sheer number of visits that its IT staff had to make to its store locations, which are spread across a number of large U.S. states.

"It was already in our code of conduct that the computers weren't to be used for this type of thing, but the tools actually allow us to enforce that," Stump said. "It's been a huge difference. All the malware has pretty much stopped, and now when we have a failure, of which there were many before, it's usually related to hardware, not viruses."

Experts debate to what extent so-called knowledge workers -- whose primary role is to work with information and who clearly need some broader level of access to the Web -- will be forced to deal with Web site and applications control, but security vendors claim that they are hearing about more aggressive plans from many different types of companies.

With security departments being pushed to become more proactive in protecting their organizations, the enforcement of less liberal Web access is likely inevitable, some experts believe.

For most workers, their level of Internet access will likely be driven by the type of job they do, the sort of business they work for, and their company's tolerance of online risk, said Doug Camplejohn, chief executive of security appliance maker Mi5 Networks.

One of Mi5's customers recently engaged in a discovery project to determine how limiting site access might affect its operations, touching off a range of new concerns.

"This bank would love to block MySpace and sites where they've seen issues from productivity and security, but it's also an interesting HR dilemma; MySpace and ESPN are among the top sites they saw in their traffic audits, and they were worried that if they block MySpace, but not ESPN, if that would be age discrimination on some level," Camplejohn said. "It will be really tough for most companies to do all or nothing; I think we'll see more of an approach whereby access is determined by who you are, and what type of work you do."