I spoke with the people at Network Appliance recently and wasn't too surprised to hear them discuss how their NetCache appliances could be used as security devices. During the past year or so, most caching companies have added security features to their gear.It just makes sense.Caches sit at the edge of your network - so why not use them as security gateways for content that travels into and out of your corporate network? When the caching market took a dive, CacheFlow, for example, decided to focus on security and last summer renamed itself Blue Coat Systems. It seems to be doing pretty well.Adding security to caches is nothing new for NetApp. NetApp was one of several caching vendors that did just that last year. But in our discussion a few weeks ago, Edward Sharp, director of the content delivery business unit at NetApp, made it clear that security had become an even bigger focus."Companies need to reduce costs at their Internet access points," he says. "We let them do that by replacing multiple proxy servers with our solutions."He says an IDC study showed that customers started seeing a return on their investment three months after replacing existing proxy servers with security-enhanced NetCache appliances.NetApp is partnering with companies such as Secure Computing, Symantec and Webwasher to add security features into the cache and to provide what NetApp is calling Internet Access and Security services. The NetCache sits behind a firewall and can provide a variety of security services, including content filtering, virus scanning, usage reporting and systems management.Sharp notes that NetApp isn't trying to get into the security business, but rather to provide a secure platform for enterprise content delivery networks."The problem is access to information, and that access must be secure," he says. "At the end of the day access to information is what drives business. That's where we keep our focus."