Monitoring conversations involves keeping an eye on what's being said over the network, and reporting policy abuse. Now, imagine doing it yourself—not only do you not win any friends but you will also kill whatever little social life you have. But a smart administrator lets the messenger do the hard work—Openfire can check messages and deliver those that meet specified criteria, and reject and report the ones that don't.
Of course, filtering objectionable IM content is important not only because it keeps the conversation clean, but also because it can be used to prevent sensitive information trespassing on your network via innocent IM conversations. But there's more to filtering conversation content than merely masking profanity. Maybe you don't want people sharing web links or non-company telephone numbers over IMs. Or maybe the company policy forbids discussing figures, budgets, and so on. Whatever the case may be, if you need a tool that'll keep an eye...