Twenty years ago, the issue was control over the center of a business where the mainframes sat. Today, it is over the edges of a business, where the firewalls sit. However, the tension between the user's interests and corporate policy is the same. The security-minded will always complain about the dangers of users controlling their own network access, just like the mainframe support staff worried that users of PCs were going to destroy their tidy environments with their copies of VisiCalc. And, like the mainframe guys, they will be right.
Security is only half the story, however.
Everyone knows that the easiest way to secure a PC is to disconnect it from the Internet, but no one outside of the NSA seriously suggests running a business where the staff has no Internet access. Security, in other words, always necessitates a tradeoff with convenience, and there are times when security can go too far. What the widespread adoption of chat software is telling us is that security concerns have gone too far, and that workers not only want more control over how and when their computers connect to the network, but that when someone offers them this control, they will take it. This is likely to make for a showdown over P2P technologies in the workplace, with an argument between the freedom of individual workers vs. the advantages of centralized control, and of security vs. flexibility. By the time general adoption of serverless intranets begins, workers will have gone too far to integrate P2P functions into their day for IT departments to simply ban them.