Blocking peer-to-peer traffic is a much bigger deal. There is no legitimate business use for Internet-based P2P file sharing in an office setting.Most P2P traffic comprises warez, porn or illegal MP3s. Anyone who says otherwise is delusional. But IM is a different story.
If you use SurfControl, IM filtering could be a natural extension of the product. Sure, plenty of other products can perform signature blocking of IM traffic. But that does not discredit the need. There are valid security reasons for blocking public IM networks. The use of recycled passwords, massive personal conversations, file transfers, spam IMs, porn spams and vulgarity are just a few of the IM challenges.
Does that mean a company should ban IM? Heck no. There are productivity gains to be made with IM, and employees are already making use of them. The desire to use IM at work is increasing and may be unstoppable. Use of IM in the enterprise is surprisingly high, though most likely not sanctioned by IT.
Don't fear IM--embrace it or roll your own. (We're testing seven do-it-yourself products for an upcoming issue.) With your own IM system, you can justify blocking public IM networks and retain the productivity boost.