It's often said that the best, and simultaneously the worst, thing about the internet is that anyone can set up a site and publish their thoughts, rants or other information. In the days of paper-only publishing, although low-volume self-publishing was certainly possible, distribution was a much more difficult issue. Reaching the handful of others interested in the same topic was, certainly for many, impractical.

The rise of the web changed that, making it trivially easy to create communities of interest over huge geographic distances. This is by and large a good thing, although like any technology it can be used by less pleasant groups of people too.
More recently, the web log, colloquially known as the "blog" (I guess we need to save syllables wherever possible), has become a must-have fashion accessory. Blogs are certainly a great way of keeping in touch with a group of friends – kind of the modern-day equivalent of the round robin letters many families used to send at Christmas – but they have also become a valuable source of information for technical staff.
For example, F-Secure's blog at www.f-secure.com/weblog is a good source of up-to-the-minute news on virus issues. Peter Finnigan also has a blog about Oracle systems that is particularly helpful for those, such as myself, who need to keep on top of the latest cracks in the "unbreakable" database product, at www.petefinnigan.com/weblog/entries. There are, no doubt, many others of use to security professionals (if you have any particular recommendations, please write in).
It isn't all good news, though. Browsing through sites such as Livejournal you will often find the sort of rants and complaints about internal company issues that really should not be in the public domain. Whereas such rants would once have been limited to lunch-time or water-cooler conversations, they are now archived and indexed for any potential attacker or social engineer to peruse. Many impromptu web publishers are unaware of the semi-permanent nature of their comments.
Of course, all information, especially that from the web, should be carefully filtered with a healthy dose of critical thinking before use. One of the benefits of professionally published material, either on paper or on the web, is the quality control applied by the editorial team.
This is by no means foolproof, but certainly reduces the risk of inaccuracy, either deliberate or accidental.
To paraphrase an old saying, caveat browser.